Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2017	Oct. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Trading Symbol	NL
Entity Registrant Name	NL INDUSTRIES INC
Entity Central Index Key	0000072162
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		48,714,884

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 96,643	$ 93,162
Restricted cash and cash equivalents	3,853	3,791
Accounts and other receivables, net	11,995	10,586
Inventories, net	15,313	14,974
Receivable from affiliate	571
Prepaid expenses and other	915	986
Total current assets	129,290	123,499
Other assets:
Notes receivable from affiliate	36,700	27,400
Marketable securities	34,926	49,731
Investment in Kronos Worldwide, Inc.	216,301	120,346
Goodwill	27,156	27,156
Other assets, net	3,570	3,276
Total other assets	318,653	227,909
Property and equipment:
Land	5,146	5,146
Buildings	23,038	22,811
Equipment	67,432	66,112
Construction in progress	680	1,098
Property and equipment, gross	96,296	95,167
Less accumulated depreciation	63,222	61,583
Net property and equipment	33,074	33,584
Total assets	481,017	384,992
Current liabilities:
Accounts payable	5,357	5,026
Accrued and other current liabilities	9,965	10,624
Accrued environmental remediation and related costs	11,400	13,350
Payable to affiliates	211	1,717
Income taxes	31	26
Total current liabilities	26,964	30,743
Noncurrent liabilities:
Long-term debt from affiliate	500	500
Accrued pension costs	11,678	12,874
Accrued postretirement benefits (OPEB) costs	2,133	2,310
Accrued environmental remediation and related costs	103,866	103,308
Deferred income taxes	56,990	27,445
Other	13,502	13,542
Total noncurrent liabilities	188,669	159,979
NL stockholders' equity:
Common stock	6,089	6,088
Additional paid-in capital	300,868	300,674
Retained earnings	170,993	104,004
Accumulated other comprehensive loss	(229,850)	(232,846)
Total NL stockholders' equity	248,100	177,920
Noncontrolling interest in subsidiary	17,284	16,350
Total equity	265,384	194,270
Total liabilities and equity	481,017	384,992
Commitments and contingencies (Note 13)

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 26,993	$ 28,404	$ 86,943	$ 82,586
Cost of sales	18,795	19,005	59,552	56,496
Gross margin	8,198	9,399	27,391	26,090
Selling, general and administrative expense	4,829	4,926	14,895	14,547
Other operating income (expense):
Insurance recoveries	103	76	219	399
Other income, net	137		140	5
Corporate expense	(2,749)	(4,555)	(11,661)	(13,538)
Income (loss) from operations	860	(6)	1,194	(1,591)
Equity in earnings of Kronos Worldwide, Inc.	22,437	6,776	93,357	6,123
Other income (expense):
Interest and dividend income	977	430	2,554	1,160
Interest expense	(8)		(22)
Income before income taxes	24,266	7,200	97,083	5,692
Income tax expense (benefit)	6,466	(560)	28,923	(1,052)
Net income	17,800	7,760	68,160	6,744
Noncontrolling interest in net income of subsidiary	328	388	1,171	996
Net income attributable to NL stockholders	$ 17,472	$ 7,372	$ 66,989	$ 5,748
Amounts attributable to NL stockholders:
Basic and diluted net income per share	$ 0.36	$ 0.15	$ 1.38	$ 0.12
Weighted average shares used in the calculation of net income per share	48,715	48,706	48,710	48,699

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income	$ 17,800	$ 7,760	$ 68,160	$ 6,744
Other comprehensive income (loss), net of tax:
Marketable securities	(5,260)	6,983	(9,851)	9,182
Currency translation	5,908	1,777	10,604	3,628
Interest rate swap	362	145	390	(583)
Total other comprehensive income, net	1,699	9,590	2,996	14,278
Comprehensive income	19,499	17,350	71,156	21,022
Comprehensive income attributable to noncontrolling interest	328	388	1,171	996
Comprehensive income attributable to NL stockholders	19,171	16,962	69,985	20,026
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	738	817	1,998	2,447
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	$ (49)	$ (132)	$ (145)	$ (396)

CONDENSED CONSOLIDATED STATEMENT OF EQUITY - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Noncontrolling interest in subsidiary
Beginning Balance at Dec. 31, 2016	$ 194,270	$ 6,088	$ 300,674	$ 104,004	$ (232,846)	$ 16,350
Net income	68,160			66,989		1,171
Other comprehensive income, net of tax	2,996				2,996
Issuance of NL common stock	83	1	82
Dividends	(250)					(250)
Other, net	125		112			13
Ending Balance at Sep. 30, 2017	$ 265,384	$ 6,089	$ 300,868	$ 170,993	$ (229,850)	$ 17,284

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 68,160	$ 6,744
Depreciation and amortization	2,794	2,847
Deferred income taxes	27,924	(1,080)
Equity in earnings of Kronos Worldwide, Inc.	(93,357)	(6,123)
Dividends received from Kronos Worldwide, Inc.	15,849	15,849
Cash funding of benefit plans in excess of net benefit plan expense	(689)	(267)
Other, net	348	385
Change in assets and liabilities:
Accounts and other receivables, net	(1,436)	(4,303)
Inventories, net	(475)	280
Prepaid expenses and other	70	125
Accounts payable and accrued liabilities	(466)	93
Income taxes	2	(4)
Accounts with affiliates	(2,062)	(34)
Accrued environmental remediation and related costs	(1,392)	3,679
Other noncurrent assets and liabilities, net	(54)	(259)
Net cash provided by operating activities	15,216	17,932
Cash flows from investing activities:
Capital expenditures	(2,152)	(2,354)
Promissory notes receivable from affiliate:
Loans	(49,700)	(15,100)
Collections	40,400	4,400
Other, net	4
Net cash used in investing activities	(11,448)	(13,054)
Cash flows from financing activities -
Distributions to noncontrolling interests in subsidiary	(250)	(249)
Cash and cash equivalents and restricted cash and cash equivalents - net change from:
Operating, investing and financing activities	3,518	4,629
Balance at beginning of period	98,242	100,981
Balance at end of period	101,760	105,610
Supplemental disclosure - cash paid for:
Interest	22
Income taxes, net	$ 3,085	$ 61

Organization and Basis of Presentation	9 Months Ended
Organization and Basis of Presentation	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and basis of presentation	Note 1 – Organization and basis of presentation: Organization – At September 30, 2017, Valhi, Inc. (NYSE: VHI) held approximately 83% of our outstanding common stock and a wholly-owned subsidiary of Contran Corporation held approximately 93% of Valhi’s outstanding common stock. All of Contran’s outstanding voting stock is held by a family trust established for the benefit of Lisa K. Simmons and Serena Simmons Connelly and their children for which Ms. Simmons and Ms. Connelly are co-trustees, or is held directly by Ms. Simmons and Ms. Connelly or entities related to them. Consequently, Ms. Simmons and Ms. Connelly may be deemed to control Contran, Valhi and us. Basis of presentation – Consolidated in this Quarterly Report are the results of our majority-owned subsidiary, CompX International Inc. We also own 30% of Kronos Worldwide, Inc. (Kronos). CompX (NYSE MKT: CIX) and Kronos (NYSE: KRO); each file periodic reports with the Securities and Exchange Commission (SEC). The unaudited Condensed Consolidated Financial Statements contained in this Quarterly Report have been prepared on the same basis as the audited Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2016 that we filed with the SEC on March 10, 2017 (the 2016 Annual Report). In our opinion, we have made all necessary adjustments (which include only normal recurring adjustments) in order to state fairly, in all material respects, our consolidated financial position, results of operations and cash flows as of the dates and for the periods presented. We have condensed the Consolidated Balance Sheet at December 31, 2016 contained in this Quarterly Report as compared to our audited Consolidated Financial Statements at that date, and we have omitted certain information and footnote disclosures (including those related to the Consolidated Balance Sheet at December 31, 2016) normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Our results of operations for the interim periods ended September 30, 2017 may not be indicative of our operating results for the full year. The Condensed Consolidated Financial Statements contained in this Quarterly Report should be read in conjunction with our 2016 Consolidated Financial Statements contained in our 2016 Annual Report. Unless otherwise indicated, references in this report to “NL,” “we,” “us” or “our” refer to NL Industries, Inc. and its subsidiaries and affiliate, Kronos, taken as a whole.

Accounts and Other Receivables, Net

9 Months Ended

Sep. 30, 2017

Receivables [Abstract]

Accounts and other receivables, net

Note 2 – Accounts and other receivables, net:

	December 31,			September 30,
	2016			2017
	(In thousands)
Trade receivables - CompX	$	10,417		$	11,787
Accrued insurance recoveries		104			139
Other receivables		135			139
Allowance for doubtful accounts		(70	)		(70	)

Total	$	10,586		$	11,995

Accrued insurance recoveries are discussed in Note 13.

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Inventories, Net

9 Months Ended

Sep. 30, 2017

Inventory Disclosure [Abstract]

Inventories, net

Note 3 – Inventories, net:

	December 31,		September 30,
	2016		2017
	(In thousands)
Raw materials	$	2,743	$	2,867
Work in process		8,988		9,684
Finished products		3,243		2,762

Total	$	14,974	$	15,313

Marketable Securities

9 Months Ended

Sep. 30, 2017

Investments Debt And Equity Securities [Abstract]

Marketable securities

Note 4 – Marketable securities:

	Fair value measurement level	Market value		Cost basis		Unrealized gain (loss)
		(In thousands)
December 31, 2016
Valhi common stock	1	$	49,731	$	24,347	$	25,384

September 30, 2017
Valhi common stock	1	$	34,926	$	24,347	$	10,579

At December 31, 2016 and September 30, 2017, we held approximately 14.4 million shares of common stock of our immediate parent company, Valhi. See Note 1. We account for our investment in Valhi common stock as available-for-sale marketable equity securities and any unrealized gains or losses on the securities are recognized through other comprehensive income, net of deferred income taxes. Our shares of Valhi common stock are carried at fair value based on quoted market prices, representing a Level 1 input within the fair value hierarchy. At December 31, 2016 and September 30, 2017, the quoted per share market price of Valhi common stock was $3.46 and $2.43, respectively.

The Valhi common stock we own is subject to the restrictions on resale pursuant to certain provisions of the SEC Rule 144. In addition, as a majority-owned subsidiary of Valhi, we cannot vote our shares of Valhi common stock under Delaware General Corporation Law, but we do receive dividends from Valhi on these shares, when declared and paid.

Investment in Kronos Worldwide, Inc.

9 Months Ended

Sep. 30, 2017

Equity Method Investments And Joint Ventures [Abstract]

Investment in Kronos Worldwide, Inc.

Note 5 – Investment in Kronos Worldwide, Inc.:

At December 31, 2016 and September 30, 2017, we owned approximately 35.2 million shares of Kronos common stock. At September 30, 2017, the quoted market price of Kronos’ common stock was $22.83 per share, or an aggregate market value of $804.1 million. At December 31, 2016, the quoted market price was $11.94 per share, or an aggregate market value of $420.5 million.

The change in the carrying value of our investment in Kronos during the first nine months of 2017 is summarized below.

	Amount
	(In millions)
Balance at the beginning of the period	$	120.3
Equity in earnings of Kronos		93.4
Dividends received from Kronos		(15.8	)
Equity in Kronos' other comprehensive income (loss):
Marketable securities		(.4	)
Currency translation		16.3
Interest rate swap		.6
Defined benefit pension plans		1.9

Balance at the end of the period	$	216.3

Selected financial information of Kronos is summarized below:

	December 31,		September 30,
	2016		2017
	(In millions)
Current assets	$	650.4	$	1,021.2
Property and equipment, net		434.0		486.2
Investment in TiO₂ joint venture		78.9		75.1
Deferred income taxes		8.1		120.0
Other noncurrent assets		8.2		7.9

Total assets	$	1,179.6	$	1,710.4

Current liabilities	$	182.1	$	240.0
Long-term debt		335.4		467.5
Accrued pension and postretirement benefits		234.2		261.6
Other noncurrent liabilities		32.9		30.6
Stockholders' equity		395.0		710.7

Total liabilities and stockholders' equity	$	1,179.6	$	1,710.4

	Three months ended				Nine months ended
	September 30,				September 30,
	2016		2017		2016		2017
	(In millions)
Net sales	$	356.1	$	464.5	$	1,030.6	$	1,275.7
Cost of sales		280.6		312.3		859.2		890.3
Income from operations		28.0		91.6		38.2		214.0
Income tax expense (benefit)		0.7		6.1		3.2		(114.0	)
Net income		22.2		73.8		20.1		307.1

Other Noncurrent Assets, Net

9 Months Ended

Sep. 30, 2017

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Other noncurrent assets, net

Note 6 – Other noncurrent assets, net:

	December 31,		September 30,
	2016		2017
	(In thousands)
Restricted cash	$	1,289	$	1,264
Pension asset		1,037		1,342
Other		950		964

Total	$	3,276	$	3,570

Accrued and Other Current Liabilities

9 Months Ended

Sep. 30, 2017

Payables And Accruals [Abstract]

Accrued and other current liabilities

Note 7 – Accrued and other current liabilities:

	December 31,		September 30,
	2016		2017
	(In thousands)
Employee benefits	$	8,375	$	7,793
Professional fees		613		555
Other		1,636		1,617

Total	$	10,624	$	9,965

Long-Term Debt	9 Months Ended
Long-Term Debt	Sep. 30, 2017
Debt Disclosure [Abstract]
Long-term debt	Note 8 – Long-term debt: During the first nine months of 2017, our wholly owned subsidiary, NLKW Holding, LLC had no borrowings or repayments under its $50 million secured revolving credit facility with Valhi. At September 30, 2017, we had outstanding borrowings of $0.5 million under such facility, and the remaining $49.5 million was available for future borrowing under this facility. Outstanding borrowings under such credit facility bear interest at the prime rate plus 1.875% per annum, and the average interest rate as of and for the nine months ended September 30, 2017 was 6.125% and 5.90%, respectively. We are in compliance with all of the covenants contained in such facility at September 30, 2017.

Employee Benefit Plans

9 Months Ended

Sep. 30, 2017

Compensation And Retirement Disclosure [Abstract]

Employee benefit plans

Note 9 – Employee benefit plans:

Defined benefit plans – The components of net periodic defined benefit pension cost are presented in the table below.

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In thousands)
Interest cost	$	585		$	506		$	1,778		$	1,518
Expected return on plan assets		(723	)		(689	)		(2,194	)		(2,067	)
Recognized actuarial losses		406			394			1,314			1,182

Total	$	268		$	211		$	898		$	633

Postretirement benefits – The components of net periodic postretirement benefits other than pension (OPEB) income are presented in the table below.

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In thousands)
Interest cost	$	24		$	20		$	72		$	60
Amortization of prior service credit		(135	)		-			(406	)		-
Recognized actuarial gains		(38	)		(54	)		(114	)		(162	)

Total	$	(149	)	$	(34	)	$	(448	)	$	(102	)

Contributions – We currently expect our 2017 contributions to our defined benefit pension plans and other postretirement plans to be approximately $1.4 million.

Other Noncurrent Liabilities

9 Months Ended

Sep. 30, 2017

Other Liabilities Disclosure [Abstract]

Other noncurrent liabilities

Note 10 – Other noncurrent liabilities:

	December 31,		September 30,
	2016		2017
	(In thousands)
Reserve for uncertain tax positions	$	12,186	$	12,186
Insurance claims and expenses		589		643
Other		767		673

Total	$	13,542	$	13,502

Income Taxes

9 Months Ended

Sep. 30, 2017

Income Tax Disclosure [Abstract]

Income taxes

Note 11 – Income taxes:

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In millions)
Expected tax expense, at U.S. federal statutory income tax rate of 35%	$	2.5		$	8.5		$	2.0		$	34.0
Rate differences on equity in earnings of Kronos		(3.0	)		(2.1	)		(2.8	)		(5.0	)
Nontaxable income		(.2	)		(.1	)		(.4	)		(.3	)
U.S. state income taxes and other, net		.1			.2			.1			.2

Income tax expense (benefit)	$	(.6	)	$	6.5		$	(1.1	)	$	28.9

Comprehensive provision for income taxes (benefit) allocable to:
Net income	$	(.6	)	$	6.5		$	(1.1	)	$	28.9
Other comprehensive income (loss):
Marketable securities		3.7			(2.8	)		4.9			(5.3	)
Currency translation		1.0			3.1			2.0			5.7
Interest rate swap		.1			.2			(.3	)		.2
Pension plans		.4			.4			1.3			1.1
OPEB plans		(.1	)		(.1	)		(.2	)		(.1	)

Total	$	4.5		$	7.3		$	6.6		$	30.5

In accordance with GAAP, we recognize deferred income taxes on our undistributed equity in earnings (losses) of Kronos. Because we and Kronos are part of the same U.S. federal income tax group, any dividends we receive from Kronos are nontaxable to us. Accordingly, we do not recognize and we are not required to pay income taxes on dividends from Kronos. We received aggregate dividends from Kronos of $15.8 million in the first nine months of 2016 and 2017. The amounts shown in the above table of our income tax rate reconciliation for rate differences on equity in earnings of Kronos represents the net tax (benefit) associated with such non-taxability of the dividends we receive from Kronos, as it relates to the amount of deferred income taxes we recognize on our undistributed equity in earnings (losses) of Kronos.

Kronos has substantial net operating loss (NOL) carryforwards in Germany (the equivalent of $638 million for Kronos’ German corporate purposes and $71 million for German trade tax purposes at December 31, 2016) and in Belgium (the equivalent of $93 million for Kronos’ Belgian corporate tax purposes at December 31, 2016), all of which have an indefinite carryforward period. As a result, Kronos has net deferred income tax assets with respect to these two jurisdictions, primarily related to these NOL carryforwards. The German corporate tax is similar to the U.S. federal income tax, and the German trade tax is similar to the U.S. state income tax. Prior to June 30, 2015, and using all available evidence, Kronos had concluded no deferred income tax asset valuation allowance was required to be recognized with respect to these net deferred income tax assets under the more-likely-than-not recognition criteria, primarily because (i) the carryforwards have an indefinite carryforward period, (ii) Kronos utilized a portion of such carryforwards during the most recent three-year period, and (iii) Kronos expected to utilize the remainder of the carryforwards over the long term. Kronos had also previously indicated that facts and circumstances could change, which might in the future result in the recognition of a valuation allowance against some or all of such deferred income tax assets. However, as of June 30, 2015, and given Kronos’ operating results during the second quarter of 2015 and Kronos’ expectations at that time for its operating results for the remainder of 2015, Kronos did not have sufficient positive evidence to overcome the significant negative evidence of having cumulative losses in the most recent twelve consecutive quarters in both its German and Belgian jurisdictions at June 30, 2015 (even considering that the carryforward period of its German and Belgian NOL carryforwards is indefinite, one piece of positive evidence). Accordingly, at June 30, 2015, Kronos concluded that it was required to recognize a non-cash deferred income tax asset valuation allowance under the more-likely-than-not recognition criteria with respect to its German and Belgian net deferred income tax assets at such date. Kronos recognized an additional non-cash deferred income tax asset valuation allowance during the second half of 2015 due to losses recognized by its German and Belgian operations during such period. During 2016, Kronos recognized an aggregate $2.2 million non-cash income tax benefit as the result of a net decrease in such deferred income tax valuation allowance, as the impact of utilizing a portion of its German NOLs during such period more than offset the impact of additional losses recognized by its Belgian operations during such period. Such valuation allowance aggregated approximately $173 million at December 31, 2016 ($153 million with respect to Germany and $20 million with respect to Belgium). During the first six months of 2017, Kronos recognized an aggregate non-cash income tax benefit of $12.7 million as a result of a net decrease in such deferred income tax asset valuation allowance, due to the utilization of a portion of both the German and Belgian NOLs during such period. At June 30, 2017, Kronos concluded it had sufficient positive evidence under the more-likely-than-not recognition criteria to support reversal of the entire valuation allowance related to Kronos’ German and Belgian operations. Such sufficient positive evidence at June 30, 2017 included, among other things, the existence of cumulative profits in the most recent twelve consecutive quarters (Germany) or profitability in recent quarters during which such profitability was trending upward throughout such period (Belgium), the ability to demonstrate future profitability in Germany and Belgium for a sustainable period, and the indefinite carryforward period for the German and Belgian NOLs. As discussed below regarding accounting for income taxes at interim dates, a large portion ($149.9 million) of the remaining valuation allowance as of June 30, 2017 was reversed in the second quarter, with the remainder to be reversed during the second half of 2017 (including $7.8 million reversed in the third quarter).

In accordance with the ASC 740-270 guidance regarding accounting for income taxes at interim dates, the amount of the valuation allowance reversed at June 30, 2017 ($149.9 million, of which $141.9 million related to Germany and $8.0 million related to Belgium) relates to Kronos’ change in judgment at that date regarding the realizability of the related deferred income tax asset as it relates to future years (i.e. 2018 and after). A change in judgment regarding the realizability of deferred tax assets as it relates to the current year is considered in determining the estimated annual effective tax rate for the year and is recognized throughout the year, including interim periods subsequent to the date of the change in judgment. Accordingly, Kronos’ income tax benefit in the first nine months of 2017 includes an aggregate non-cash income tax benefit of $170.4 million related to the reversal of the German and Belgian valuation allowance, comprised of $12.7 million recognized in the first six months of 2017 related to the utilization of a portion of both the German and Belgian NOLs during such period, $149.9 million related to the portion of the valuation allowance reversed as of June 30, 2017, and $7.8 million recognized in the third quarter of 2017 related to the utilization of a portion of both the German and Belgian NOLs during such period. In addition, Kronos’ deferred income tax asset valuation allowance increased $9.0 million in the first nine months of 2017 as a result of changes in currency exchange rates, which increase was recognized as part of other comprehensive income (loss). The remaining deferred income tax asset valuation allowance of $11.7 million as of September 30, 2017 will be reversed during the fourth quarter of 2017, and our share of such reversal will be included in our equity in earnings from Kronos for such period.

Tax authorities are examining certain of Kronos’ U.S. and non-U.S. tax returns and have or may propose tax deficiencies, including penalties and interest. Because of the inherent uncertainties involved in settlement initiatives and court and tax proceedings, Kronos cannot guarantee that these matters will be resolved in its favor, and therefore Kronos’ potential exposure, if any, is also uncertain. As a result of ongoing audits in certain jurisdictions, in 2008 Kronos filed Advance Pricing Agreement Requests with the tax authorities in the U.S., Canada and Germany. These requests have been under review with the respective tax authorities since 2008 and prior to 2016, it was uncertain whether an agreement would be reached between the tax authorities and whether Kronos would agree to execute and finalize such agreements.

•

During the third quarter of 2016, Contran, as the ultimate parent of Kronos’ U.S. Consolidated income tax group, executed and finalized an Advance Pricing Agreement with the U.S. Internal Revenue Service and Kronos’ Canadian subsidiary executed and finalized an Advance Pricing Agreement with the Competent Authority for Canada (collectively, the “U.S.-Canada APA”) effective for tax years 2005 - 2015. Pursuant to the terms of the U.S.-Canada APAs, the U.S. and Canadian tax authorities agreed to certain prior year changes to taxable income of Kronos’ U.S. and Canadian subsidiaries. As a result of such agreed-upon changes, Kronos recognized a $5.6 million current U.S. income tax benefit in the third quarter of 2016. In addition, Kronos’ Canadian subsidiary incurred a cash income tax payment of approximately CAD $3 million (USD $2.3 million) related to the U.S.-Canada APA, but such payment was fully offset by previously provided accruals, and such income tax was paid in the third quarter of 2017.

•

During the third quarter of 2017, Kronos’ Canadian subsidiary executed and finalized an Advance Pricing Agreement with the Competent Authority for Canada (the “Canada-Germany APA”) effective for tax years 2005 - 2017. Pursuant to the terms of the Canada-Germany APA, the Canadian and German tax authorities agreed to certain prior year changes to taxable income of Kronos’ Canadian and German subsidiaries. As a result of such agreed-upon changes, Kronos reversed a significant portion of its reserve for uncertain tax positions and recognized an aggregate income tax benefit of $11.3 million, including a non-cash income tax benefit of $8.1 million related to such reversal in the third quarter of 2017. In addition, Kronos recognized a $2.6 million non-cash income tax benefit related to an increase in its German NOLs and a $.6 million German cash tax refund related to the Canada-Germany APA in the third quarter of 2017.

We believe we have adequate accruals for additional taxes and related interest expense which could ultimately result from tax examinations. We believe the ultimate disposition of tax examinations should not have a material adverse effect on our consolidated financial position, results of operations or liquidity. We currently estimate that our unrecognized tax benefits will not change materially during the next twelve months.

Accumulated Other Comprehensive Income (Loss)

9 Months Ended

Sep. 30, 2017

Stockholders Equity Note [Abstract]

Accumulated other comprehensive income (loss)

Note 12 – Accumulated other comprehensive income (loss):

Changes in accumulated other comprehensive income (loss) attributable to NL stockholders, including amounts resulting from our investment in Kronos Worldwide (see Note 5), are presented in the table below.

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017

Accumulated other comprehensive loss, net of tax:
Marketable securities:
Balance at beginning of period	$	2,394		$	15,882		$	195		$	20,473
Other comprehensive income (loss) - unrealized gains (losses) arising during the year		6,983			(5,260	)		9,182			(9,851	)

Balance at end of period	$	9,377		$	10,622		$	9,377		$	10,622

Currency translation:
Balance at beginning of period	$	(170,533	)	$	(171,163	)	$	(172,384	)	$	(175,859	)
Other comprehensive income		1,777			5,908			3,628			10,604

Balance at end of period	$	(168,756	)	$	(165,255	)	$	(168,756	)	$	(165,255	)

Interest rate swap:
Balance at beginning of period	$	(1,173	)	$	(362	)	$	(445	)	$	(390	)
Other comprehensive income (loss):
Unrealized gains (losses) arising during the year		32			(119	)		(920	)		(296	)
Less reclassification adjustment for amounts included in interest expense		113			481			337			686

Balance at end of period	$	(1,028	)	$	-		$	(1,028	)	$	-

Defined benefit pension plans:
Balance at beginning of period	$	(71,082	)	$	(75,450	)	$	(72,712	)	$	(76,710	)
Other comprehensive income - amortization of net losses included in net periodic pension cost		817			738			2,447			1,998

Balance at end of period	$	(70,265	)	$	(74,712	)	$	(70,265	)	$	(74,712	)

OPEB plans:
Balance at beginning of period	$	(276	)	$	(456	)	$	(12	)	$	(360	)
Other comprehensive loss - amortization of prior service credit and net gains included in net periodic OPEB cost		(132	)		(49	)		(396	)		(145	)

Balance at end of period	$	(408	)	$	(505	)	$	(408	)	$	(505	)

Total accumulated other comprehensive loss:
Balance at beginning of period	$	(240,670	)	$	(231,549	)	$	(245,358	)	$	(232,846	)
Other comprehensive income		9,590			1,699			14,278			2,996

Balance at end of period	$	(231,080	)	$	(229,850	)	$	(231,080	)	$	(229,850	)

See Note 9 for amounts related to our defined benefit pension plans and OPEB plans.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2017

Commitments And Contingencies Disclosure [Abstract]

Commitments and contingencies

Note 13 – Commitments and contingencies:

General

We are involved in various environmental, contractual, product liability, patent (or intellectual property), employment and other claims and disputes incidental to our current and former businesses. At least quarterly our management discusses and evaluates the status of any pending litigation or claim to which we are a party or which has been asserted against us. The factors considered in such evaluation include, among other things, the nature of such pending cases and claims, the status of such pending cases and claims, the advice of legal counsel and our experience in similar cases and claims (if any). Based on such evaluation, we make a determination as to whether we believe (i) it is probable a loss has been incurred, and if so if the amount of such loss (or a range of loss) is reasonably estimable, or (ii) it is reasonably possible but not probable a loss has been incurred, and if so if the amount of such loss (or a range of loss) is reasonably estimable, or (iii) the probability a loss has been incurred is remote.

Lead pigment litigation

Our former operations included the manufacture of lead pigments for use in paint and lead-based paint. We, other former manufacturers of lead pigments for use in paint and lead-based paint (together, the “former pigment manufacturers”), and the Lead Industries Association (LIA), which discontinued business operations in 2002, have been named as defendants in various legal proceedings seeking damages for personal injury, property damage and governmental expenditures allegedly caused by the use of lead-based paints. Certain of these actions have been filed by or on behalf of states, counties, cities or their public housing authorities and school districts, and certain others have been asserted as class actions. These lawsuits seek recovery under a variety of theories, including public and private nuisance, negligent product design, negligent failure to warn, strict liability, breach of warranty, conspiracy/concert of action, aiding and abetting, enterprise liability, market share or risk contribution liability, intentional tort, fraud and misrepresentation, violations of state consumer protection statutes, supplier negligence and similar claims.

The plaintiffs in these actions generally seek to impose on the defendants responsibility for lead paint abatement and health concerns associated with the use of lead-based paints, including damages for personal injury, contribution and/or indemnification for medical expenses, medical monitoring expenses and costs for educational programs. To the extent the plaintiffs seek compensatory or punitive damages in these actions, such damages are generally unspecified. In some cases, the damages are unspecified pursuant to the requirements of applicable state law. A number of cases are inactive or have been dismissed or withdrawn. Most of the remaining cases are in various pre-trial stages. Some are on appeal following dismissal or summary judgment rulings or a trial verdict in favor of either the defendants or the plaintiffs.

We believe that these actions are without merit, and we intend to continue to deny all allegations of wrongdoing and liability and to defend against all actions vigorously. We do not believe it is probable that we have incurred any liability with respect to all of the lead pigment litigation cases to which we are a party, and liability to us that may result, if any, in this regard cannot be reasonably estimated, because:

•

we have never settled any of the market share, intentional tort, fraud, nuisance, supplier negligence, breach of warranty, conspiracy, misrepresentation, aiding and abetting, enterprise liability, or statutory cases,

•

no final, non-appealable adverse verdicts have ever been entered against us, and

•

we have never ultimately been found liable with respect to any such litigation matters, including over 100 cases over a twenty-year period for which we were previously a party and for which we have been dismissed without any finding of liability.

Accordingly, we have not accrued any amounts for any of the pending lead pigment and lead—based paint litigation cases filed by or on behalf of states, counties, cities or their public housing authorities and school districts, or those asserted as class actions. In addition, we have determined that liability to us which may result, if any, cannot be reasonably estimated because there is no prior history of a loss of this nature on which an estimate could be made and there is no substantive information available upon which an estimate could be based.

In one of these lead pigment cases, in April 2000 we were served with a complaint in County of Santa Clara v. Atlantic Richfield Company, et al. (Superior Court of the State of California, County of Santa Clara, Case No. 1-00-CV-788657) brought by a number of California government entities against the former pigment manufacturers, the LIA and certain paint manufacturers. The County of Santa Clara sought to recover compensatory damages for funds the plaintiffs have expended or would in the future expend for medical treatment, educational expenses, abatement or other costs due to exposure to, or potential exposure to, lead paint, disgorgement of profit, and punitive damages. In July 2003, the trial judge granted defendants’ motion to dismiss all remaining claims. Plaintiffs appealed and the intermediate appellate court reinstated public nuisance, negligence, strict liability, and fraud claims in March 2006. A fourth amended complaint was filed in March 2011 on behalf of The People of California by the County Attorneys of Alameda, Ventura, Solano, San Mateo, Los Angeles and Santa Clara, and the City Attorneys of San Francisco, San Diego and Oakland. That complaint alleged that the presence of lead paint created a public nuisance in each of the prosecuting jurisdictions and sought its abatement. In July and August 2013, the case was tried. In January 2014, the Judge issued a judgment finding us, The Sherwin Williams Company and ConAgra Grocery Products Company jointly and severally liable for the abatement of lead paint in pre-1980 homes, and ordered the defendants to pay an aggregate $1.15 billion to the people of the State of California to fund such abatement. In February 2014, we filed a motion for a new trial, and in March 2014 the court denied the motion. Subsequently in March 2014, we filed a notice of appeal with the Sixth District Court of Appeal for the State of California and the appeal is proceeding with the appellate court. The California Sixth District Court of Appeal held oral argument on the appeal of the lower court decision on August 24, 2017, and the appellate court has not yet ruled. NL believes that this judgment is inconsistent with California law and is unsupported by the evidence, and we will defend vigorously against all claims.

The Santa Clara case is unusual in that this is the second time that an adverse verdict in the lead pigment litigation has been entered against NL (the first adverse verdict against NL was ultimately overturned on appeal). We have concluded that the likelihood of a loss in this case has not reached a standard of “probable” as contemplated by ASC 450, given (i) the substantive, substantial and meritorious grounds on which the adverse verdict in the Santa Clara case will be appealed, (ii) the uniqueness of the Santa Clara verdict (i.e. no final, non-appealable verdicts have ever been rendered against us, or any of the other former lead pigment manufacturers, based on the public nuisance theory of liability or otherwise), and (iii) the rejection of the public nuisance theory of liability as it relates to lead pigment matters in many other jurisdictions (no jurisdiction in which a plaintiff has asserted a public nuisance theory of liability has ever successfully been upheld). In addition, liability that may result, if any, cannot be reasonably estimated, as NL continues to have no basis on which an estimate of liability could be made, as discussed above. However, as with any legal proceeding, there is no assurance that any appeal would be successful, and it is reasonably possible, based on the outcome of the appeals process, that NL may in the future incur some liability resulting in the recognition of a loss contingency accrual that could have a material adverse impact on our results of operations, financial position and liquidity.

New cases may continue to be filed against us. We do not know if we will incur liability in the future in respect of any of the pending or possible litigation in view of the inherent uncertainties involved in court and jury rulings. In the future, if new information regarding such matters becomes available to us (such as a final, non-appealable adverse verdict against us or otherwise ultimately being found liable with respect to such matters), at that time we would consider such information in evaluating any remaining cases then-pending against us as to whether it might then have become probable we have incurred liability with respect to these matters, and whether such liability, if any, could have become reasonably estimable. The resolution of any of these cases could result in the recognition of a loss contingency accrual that could have a material adverse impact on our net income for the interim or annual period during which such liability is recognized and a material adverse impact on our consolidated financial condition and liquidity.

Environmental matters and litigation

Our operations are governed by various environmental laws and regulations. Certain of our businesses are and have been engaged in the handling, manufacture or use of substances or compounds that may be considered toxic or hazardous within the meaning of applicable environmental laws and regulations. As with other companies engaged in similar businesses, certain of our past and current operations and products have the potential to cause environmental or other damage. We have implemented and continue to implement various policies and programs in an effort to minimize these risks. Our policy is to maintain compliance with applicable environmental laws and regulations at all of our plants and to strive to improve environmental performance. From time to time, we may be subject to environmental regulatory enforcement under U.S. and non-U.S. statutes, the resolution of which typically involves the establishment of compliance programs. It is possible that future developments, such as stricter requirements of environmental laws and enforcement policies, could adversely affect our production, handling, use, storage, transportation, sale or disposal of such substances. We believe that all of our facilities are in substantial compliance with applicable environmental laws.

Certain properties and facilities used in our former operations, including divested primary and secondary lead smelters and former mining locations, are the subject of civil litigation, administrative proceedings or investigations arising under federal and state environmental laws and common law. Additionally, in connection with past operating practices, we are currently involved as a defendant, potentially responsible party (PRP) or both, pursuant to the Comprehensive Environmental Response, Compensation and Liability Act, as amended by the Superfund Amendments and Reauthorization Act (CERCLA), and similar state laws in various governmental and private actions associated with waste disposal sites, mining locations, and facilities that we or our predecessors, our subsidiaries or their predecessors currently or previously owned, operated or used, certain of which are on the United States Environmental Protection Agency’s (EPA) Superfund National Priorities List or similar state lists. These proceedings seek cleanup costs, damages for personal injury or property damage and/or damages for injury to natural resources. Certain of these proceedings involve claims for substantial amounts. Although we may be jointly and severally liable for these costs, in most cases we are only one of a number of PRPs who may also be jointly and severally liable, and among whom costs may be shared or allocated. In addition, we are occasionally named as a party in a number of personal injury lawsuits filed in various jurisdictions alleging claims related to environmental conditions alleged to have resulted from our operations.

Obligations associated with environmental remediation and related matters are difficult to assess and estimate for numerous reasons including the:

•

complexity and differing interpretations of governmental regulations,

•

number of PRPs and their ability or willingness to fund such allocation of costs,

•

financial capabilities of the PRPs and the allocation of costs among them,

•

solvency of other PRPs,

•

multiplicity of possible solutions,

•

number of years of investigatory, remedial and monitoring activity required,

•

uncertainty over the extent, if any, to which our former operations might have contributed to the conditions allegedly giving rise to such personal injury, property damage, natural resource and related claims, and

•

number of years between former operations and notice of claims and lack of information and documents about the former operations.

In addition, the imposition of more stringent standards or requirements under environmental laws or regulations, new developments or changes regarding site cleanup costs or the allocation of costs among PRPs, solvency of other PRPs, the results of future testing and analysis undertaken with respect to certain sites or a determination that we are potentially responsible for the release of hazardous substances at other sites, could cause our expenditures to exceed our current estimates. We do not know if actual costs will exceed accrued amounts or the upper end of the range for sites for which estimates have been made, and we do not know if costs will be incurred for sites where no estimates presently can be made. Further, additional environmental and related matters may arise in the future. If we were to incur any future liability, this could have a material adverse effect on our consolidated financial statements, results of operations and liquidity.

We record liabilities related to environmental remediation and related matters (including costs associated with damages for personal injury or property damage and/or damages for injury to natural resources) when estimated future expenditures are probable and reasonably estimable. We adjust such accruals as further information becomes available to us or as circumstances change. Unless the amounts and timing of such estimated future expenditures are fixed and reasonably determinable, we generally do not discount estimated future expenditures to their present value due to the uncertainty of the timing of the payout. We recognize recoveries of costs from other parties, if any, as assets when their receipt is deemed probable. At December 31, 2016 and September 30, 2017, we have not recognized any receivables for recoveries.

We do not know and cannot estimate the exact time frame over which we will make payments for our accrued environmental and related costs. The timing of payments depends upon a number of factors, including but not limited to the timing of the actual remediation process; which in turn depends on factors outside of our control. At each balance sheet date, we estimate the amount of our accrued environmental and related costs which we expect to pay within the next twelve months, and we classify this estimate as a current liability. We classify the remaining accrued environmental costs as a noncurrent liability.

Changes in the accrued environmental remediation and related costs during the first nine months of 2017 are as follows:

	Amount
	(In thousands)
Balance at the beginning of the period	$	116,658
Additions charged to expense, net		3,236
Payments, net		(4,628	)

Balance at the end of the period	$	115,266

Amounts recognized in the Condensed Consolidated
Balance Sheet at the end of the period:
Current liability	$	11,400
Noncurrent liability		103,866

Balance at the end of the period	$	115,266

On a quarterly basis, we evaluate the potential range of our liability for environmental remediation and related costs at sites where we have been named as a PRP or defendant, including sites for which our wholly-owned environmental management subsidiary, NL Environmental Management Services, Inc. (EMS), has contractually assumed our obligations. At September 30, 2017, we had accrued approximately $115 million related to approximately 38 sites associated with remediation and related matters that we believe are at the present time and/or in their current phase reasonably estimable. The upper end of the range of reasonably possible costs to us for remediation and related matters for which we believe it is possible to estimate costs is approximately $157 million, including the amount currently accrued. These accruals have not been discounted to present value.

We believe that it is not reasonably possible to estimate the range of costs for certain sites. At September 30, 2017, there were approximately 5 sites for which we are not currently able to reasonably estimate a range of costs. For these sites, generally the investigation is in the early stages, and we are unable to determine whether or not we actually had any association with the site, the nature of our responsibility for the contamination at the site, if any, and the extent of contamination at and cost to remediate the site. The timing and availability of information on these sites is dependent on events outside of our control, such as when the party alleging liability provides information to us. At certain of these previously inactive sites, we have received general and special notices of liability from the EPA and/or state agencies alleging that we, sometimes with other PRPs, are liable for past and future costs of remediating environmental contamination allegedly caused by former operations. These notifications may assert that we, along with any other alleged PRPs, are liable for past and/or future clean-up costs. As further information becomes available to us for any of these sites, which would allow us to estimate a range of costs, we would at that time adjust our accruals. Any such adjustment could result in the recognition of an accrual that would have a material effect on our consolidated financial statements, results of operations and liquidity.

Insurance coverage claims

We are involved in certain legal proceedings with a number of our former insurance carriers regarding the nature and extent of the carriers’ obligations to us under insurance policies with respect to certain lead pigment and asbestos lawsuits. The issue of whether insurance coverage for defense costs or indemnity or both will be found to exist for our lead pigment and asbestos litigation depends upon a variety of factors and we cannot assure you that such insurance coverage will be available.

We have agreements with certain of our former insurance carriers pursuant to which the carriers reimburse us for a portion of our future lead pigment litigation defense costs, and one such carrier reimburses us for a portion of our future asbestos litigation defense costs. We are not able to determine how much we will ultimately recover from these carriers for defense costs incurred by us because of certain issues that arise regarding which defense costs qualify for reimbursement. While we continue to seek additional insurance recoveries, we do not know if we will be successful in obtaining reimbursement for either defense costs or indemnity. Accordingly, we recognize insurance recoveries in income only when receipt of the recovery is probable and we are able to reasonably estimate the amount of the recovery.

For a complete discussion of certain litigation involving us and certain of our former insurance carriers, refer to our 2016 Annual Report.

Other litigation

We have been named as a defendant in various lawsuits in several jurisdictions, alleging personal injuries as a result of occupational exposure primarily to products manufactured by our former operations containing asbestos, silica and/or mixed dust. In addition, some plaintiffs allege exposure to asbestos from working in various facilities previously owned and/or operated by us. There are 103 of these types of cases pending, involving a total of approximately 587 plaintiffs. In addition, the claims of approximately 8,680 plaintiffs have been administratively dismissed or placed on the inactive docket in Ohio state court. We do not expect these claims will be re-opened unless the plaintiffs meet the courts’ medical criteria for asbestos-related claims. We have not accrued any amounts for this litigation because of the uncertainty of liability and inability to reasonably estimate the liability, if any. To date, we have not been adjudicated liable in any of these matters.

Based on information available to us, including:

•

facts concerning historical operations,

•

the rate of new claims,

•

the number of claims from which we have been dismissed, and

•

our prior experience in the defense of these matters,

we believe that the range of reasonably possible outcomes of these matters will be consistent with our historical costs (which are not material). Furthermore, we do not expect any reasonably possible outcome would involve amounts material to our consolidated financial position, results of operations or liquidity. We have sought and will continue to vigorously seek, dismissal and/or a finding of no liability from each claim. In addition, from time to time, we have received notices regarding asbestos or silica claims purporting to be brought against former subsidiaries, including notices provided to insurers with which we have entered into settlements extinguishing certain insurance policies. These insurers may seek indemnification from us. For a discussion of other legal proceedings to which we are a party, refer to our 2016 Annual Report.

In addition to the litigation described above, we and our affiliates are also involved in various other environmental, contractual, product liability, patent (or intellectual property), employment and other claims and disputes incidental to present and former businesses. In certain cases, we have insurance coverage for these items, although we do not expect additional material insurance coverage for environmental matters.

We currently believe the disposition of all of these various other claims and disputes, individually and in the aggregate, should not have a material adverse effect on our consolidated financial position, results of operations or liquidity beyond the accruals already provided.

Financial Instruments and Fair Value Measurements

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Financial instruments and fair value measurements

Note 14 – Financial instruments and fair value measurements:

See Note 4 for information on how we determine fair value of our marketable securities.

The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure:

	December 31, 2016				September 30, 2017
	Carrying		Fair		Carrying		Fair
	amount		value		amount		value
	(In thousands)
Cash, cash equivalents and restricted cash	$	98,242	$	98,242	$	101,760	$	101,760
Noncontrolling interest in CompX common stock		16,350		26,790		17,284		25,483

The fair value of our noncontrolling interest in CompX stockholders’ equity is based upon its quoted market price at each balance sheet date, which represents a Level 1 input. Due to their near-term maturities, the carrying amounts of accounts receivable and accounts payable are considered equivalent to fair value.

Recent Accounting Pronouncements	9 Months Ended
Recent Accounting Pronouncements	Sep. 30, 2017
Accounting Changes And Error Corrections [Abstract]
Recent accounting pronouncements	Note 15 – Recent accounting pronouncements: Adopted In January 2017, the FASB issued ASU 2017-04, Intangibles— Goodwill and Other (Topic 350) Simplifying the Test for Goodwill Impairment, which aims to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Previously, Step 2 measured a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, under the new ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and a goodwill impairment charge would be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value. In no circumstances would the loss recognized exceed the total amount of goodwill allocated to that reporting unit. We have elected to adopt this ASU beginning with our goodwill impairment test performed in the third quarter of 2017. The application of ASU 2017-04 did not have a material effect on our Condensed Consolidated Financial Statements. Pending adoption In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606). This standard replaces existing revenue recognition guidance, which in many cases was tailored for specific industries, with a uniform accounting standard applicable to all industries and transactions. The new standard, as amended, is currently effective for us beginning with the first quarter of 2018. Entities may elect to adopt ASU No. 2014-09 retrospectively for all periods for all contracts and transactions which occurred during the period (with a few exceptions for practical expediency) or retrospectively with a cumulative effect recognized as of the date of adoption. ASU No. 2014-09 is a fundamental rewriting of existing GAAP with respect to revenue recognition. We expect to adopt the standard in the first quarter of 2018 using the modified retrospective approach to adoption. Our sales generally involve single performance obligations to ship goods pursuant to customer purchase orders without further underlying contracts, and as such, we expect adoption of this standard will have a minimal effect on our revenues. We are in the process of evaluating the additional disclosure requirements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects related to the recognition, measurement, presentation and disclosure of financial instruments. The ASU requires equity investments (except for those accounted for under the equity method of accounting or those that result in the consolidation of the investee) to generally be measured at fair value with changes in fair value recognized in net income. The amendment also requires a number of other changes, including among others: simplifying the impairment assessment for equity instruments without readily determinable fair values; eliminating the requirement for public business entities to disclose method and assumptions used to determine fair value for financial instruments measured at amortized cost; requiring an exit price notion when measuring the fair value of financial instruments for disclosure purposes; and requiring separate presentation of financial assets and liabilities by measurement category and form of asset. The changes indicated above will be effective for us beginning in the first quarter of 2018, with prospective application required, and early adoption is not permitted. The most significant aspect of adopting this ASU will be the requirement to recognize changes in fair value of our available-for-sale marketable equity securities in net income (currently changes in fair value of such securities are recognized in other comprehensive income). In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which is a comprehensive rewriting of the lease accounting guidance which aims to increase comparability and transparency with regard to lease transactions. The primary change will be the recognition of lease assets for the right-of-use of the underlying asset and lease liabilities for the obligation to make payments by lessees on the balance sheet for leases currently classified as operating leases. The ASU also requires increased qualitative disclosure about leases in addition to quantitative disclosures currently required. Companies are required to use a modified retrospective approach to adoption with a practical expedient which will allow companies to continue to account for existing leases under the prior guidance unless a lease is modified, other than the requirement to recognize the right-of-use asset and lease liability for all operating leases. The changes indicated above will be effective for us beginning in the first quarter of 2019, with early adoption permitted. We are in the process of assessing all of our current leases. We have not yet evaluated the effect this ASU will have on our Consolidated Financial Statements, but given the insignificant amount of our future minimum payments under non-cancellable operating leases at December 31, 2016 discussed in Note 17 to our 2016 Annual Report, we do not expect the adoption of this standard to have a material effect on our Consolidated Balance Sheets. In March 2017, the FASB issued ASU 2017-07, Compensation— Retirement Benefits (Topic 715) Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires that the service cost component of net periodic defined benefit pension and OPEB cost be reported in the same line item as other compensation costs for applicable employees incurred during the period. Other components of such net benefit cost are required to be presented in the income statement separately from the service cost component, and below income from operations (if such a subtotal is presented). These other net benefit cost components must be disclosed either on the face of the financial statements or in the notes to the financial statements. In addition only the service cost component is eligible for capitalization in assets where applicable (inventory or internally constructed fixed assets for example). The amendments in ASU 2017-06 are effective for us beginning with in the first quarter of 2018, early adoption as of the beginning of an annual period is permitted, retrospective presentation is required for the income statement presentation of the service cost component and other components of net benefit cost, and prospective application is required for the capitalization in assets of the service cost component of net benefit cost. We expect to adopt this ASU in the first quarter of 2018. Our net benefit cost for both defined benefit pension plans and OPEB plans does not include any service cost component, none of such net benefit costs are capitalized in assets, we present a subtotal for income from operations and our net benefit cost is currently included in the determination of income from operations. Accordingly, adoption of this standard will change the determination of the amount we report as income from operations. As disclosed in Note 11 to our 2016 Annual Report, our total net periodic defined benefit pension costs were $865,000 in 2016, and our net periodic OPEB cost was a credit of $597,000 during 2016.

Organization and Basis of Presentation (Policies)	9 Months Ended
Organization and Basis of Presentation (Policies)	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Organization – At September 30, 2017, Valhi, Inc. (NYSE: VHI) held approximately 83% of our outstanding common stock and a wholly-owned subsidiary of Contran Corporation held approximately 93% of Valhi’s outstanding common stock. All of Contran’s outstanding voting stock is held by a family trust established for the benefit of Lisa K. Simmons and Serena Simmons Connelly and their children for which Ms. Simmons and Ms. Connelly are co-trustees, or is held directly by Ms. Simmons and Ms. Connelly or entities related to them. Consequently, Ms. Simmons and Ms. Connelly may be deemed to control Contran, Valhi and us.
Basis of presentation	Basis of presentation – Consolidated in this Quarterly Report are the results of our majority-owned subsidiary, CompX International Inc. We also own 30% of Kronos Worldwide, Inc. (Kronos). CompX (NYSE MKT: CIX) and Kronos (NYSE: KRO); each file periodic reports with the Securities and Exchange Commission (SEC). The unaudited Condensed Consolidated Financial Statements contained in this Quarterly Report have been prepared on the same basis as the audited Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2016 that we filed with the SEC on March 10, 2017 (the 2016 Annual Report). In our opinion, we have made all necessary adjustments (which include only normal recurring adjustments) in order to state fairly, in all material respects, our consolidated financial position, results of operations and cash flows as of the dates and for the periods presented. We have condensed the Consolidated Balance Sheet at December 31, 2016 contained in this Quarterly Report as compared to our audited Consolidated Financial Statements at that date, and we have omitted certain information and footnote disclosures (including those related to the Consolidated Balance Sheet at December 31, 2016) normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Our results of operations for the interim periods ended September 30, 2017 may not be indicative of our operating results for the full year. The Condensed Consolidated Financial Statements contained in this Quarterly Report should be read in conjunction with our 2016 Consolidated Financial Statements contained in our 2016 Annual Report. Unless otherwise indicated, references in this report to “NL,” “we,” “us” or “our” refer to NL Industries, Inc. and its subsidiaries and affiliate, Kronos, taken as a whole.

Accounts and Other Receivables, Net (Tables)

9 Months Ended

Sep. 30, 2017

Receivables [Abstract]

Schedule of Accounts Notes Loans and Financing Receivable

	December 31,			September 30,
	2016			2017
	(In thousands)
Trade receivables - CompX	$	10,417		$	11,787
Accrued insurance recoveries		104			139
Other receivables		135			139
Allowance for doubtful accounts		(70	)		(70	)

Total	$	10,586		$	11,995

Inventories, Net (Tables)

9 Months Ended

Sep. 30, 2017

Inventory Disclosure [Abstract]

Schedule of Inventories, Net

	December 31,		September 30,
	2016		2017
	(In thousands)
Raw materials	$	2,743	$	2,867
Work in process		8,988		9,684
Finished products		3,243		2,762

Total	$	14,974	$	15,313

Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2017

Investments Debt And Equity Securities [Abstract]

Schedule of Marketable Securities

	Fair value measurement level	Market value		Cost basis		Unrealized gain (loss)
		(In thousands)
December 31, 2016
Valhi common stock	1	$	49,731	$	24,347	$	25,384

September 30, 2017
Valhi common stock	1	$	34,926	$	24,347	$	10,579

Investment in Kronos Worldwide, Inc. (Tables)

9 Months Ended

Sep. 30, 2017

Equity Method Investments And Joint Ventures [Abstract]

Changes in Carrying Value of Investment

The change in the carrying value of our investment in Kronos during the first nine months of 2017 is summarized below.

	Amount
	(In millions)
Balance at the beginning of the period	$	120.3
Equity in earnings of Kronos		93.4
Dividends received from Kronos		(15.8	)
Equity in Kronos' other comprehensive income (loss):
Marketable securities		(.4	)
Currency translation		16.3
Interest rate swap		.6
Defined benefit pension plans		1.9

Balance at the end of the period	$	216.3

Selected Financial Information of Kronos Balance Sheet

Selected financial information of Kronos is summarized below:

	December 31,		September 30,
	2016		2017
	(In millions)
Current assets	$	650.4	$	1,021.2
Property and equipment, net		434.0		486.2
Investment in TiO₂ joint venture		78.9		75.1
Deferred income taxes		8.1		120.0
Other noncurrent assets		8.2		7.9

Total assets	$	1,179.6	$	1,710.4

Current liabilities	$	182.1	$	240.0
Long-term debt		335.4		467.5
Accrued pension and postretirement benefits		234.2		261.6
Other noncurrent liabilities		32.9		30.6
Stockholders' equity		395.0		710.7

Total liabilities and stockholders' equity	$	1,179.6	$	1,710.4

Selected Financial Information of Kronos Income Statement

	Three months ended				Nine months ended
	September 30,				September 30,
	2016		2017		2016		2017
	(In millions)
Net sales	$	356.1	$	464.5	$	1,030.6	$	1,275.7
Cost of sales		280.6		312.3		859.2		890.3
Income from operations		28.0		91.6		38.2		214.0
Income tax expense (benefit)		0.7		6.1		3.2		(114.0	)
Net income		22.2		73.8		20.1		307.1

Other Noncurrent Assets, Net (Tables)

9 Months Ended

Sep. 30, 2017

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Summary of Other Noncurrent Assets

	December 31,		September 30,
	2016		2017
	(In thousands)
Restricted cash	$	1,289	$	1,264
Pension asset		1,037		1,342
Other		950		964

Total	$	3,276	$	3,570

Accrued and Other Current Liabilities (Tables)

9 Months Ended

Sep. 30, 2017

Payables And Accruals [Abstract]

Schedule of Accrued and Other Current Liabilities

	December 31,		September 30,
	2016		2017
	(In thousands)
Employee benefits	$	8,375	$	7,793
Professional fees		613		555
Other		1,636		1,617

Total	$	10,624	$	9,965

Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2017

Defined Benefit Pension Plans

Components of Net Periodic Defined Benefit Cost (Income)

Defined benefit plans – The components of net periodic defined benefit pension cost are presented in the table below.

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In thousands)
Interest cost	$	585		$	506		$	1,778		$	1,518
Expected return on plan assets		(723	)		(689	)		(2,194	)		(2,067	)
Recognized actuarial losses		406			394			1,314			1,182

Total	$	268		$	211		$	898		$	633

OPEB

Components of Net Periodic Defined Benefit Cost (Income)

Postretirement benefits – The components of net periodic postretirement benefits other than pension (OPEB) income are presented in the table below.

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In thousands)
Interest cost	$	24		$	20		$	72		$	60
Amortization of prior service credit		(135	)		-			(406	)		-
Recognized actuarial gains		(38	)		(54	)		(114	)		(162	)

Total	$	(149	)	$	(34	)	$	(448	)	$	(102	)

Other Noncurrent Liabilities (Tables)

9 Months Ended

Sep. 30, 2017

Other Liabilities Disclosure [Abstract]

Summary of Other Noncurrent Liabilities

	December 31,		September 30,
	2016		2017
	(In thousands)
Reserve for uncertain tax positions	$	12,186	$	12,186
Insurance claims and expenses		589		643
Other		767		673

Total	$	13,542	$	13,502

Income Taxes (Tables)

9 Months Ended

Sep. 30, 2017

Income Tax Disclosure [Abstract]

Component of Income Taxes

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017
	(In millions)
Expected tax expense, at U.S. federal statutory income tax rate of 35%	$	2.5		$	8.5		$	2.0		$	34.0
Rate differences on equity in earnings of Kronos		(3.0	)		(2.1	)		(2.8	)		(5.0	)
Nontaxable income		(.2	)		(.1	)		(.4	)		(.3	)
U.S. state income taxes and other, net		.1			.2			.1			.2

Income tax expense (benefit)	$	(.6	)	$	6.5		$	(1.1	)	$	28.9

Comprehensive provision for income taxes (benefit) allocable to:
Net income	$	(.6	)	$	6.5		$	(1.1	)	$	28.9
Other comprehensive income (loss):
Marketable securities		3.7			(2.8	)		4.9			(5.3	)
Currency translation		1.0			3.1			2.0			5.7
Interest rate swap		.1			.2			(.3	)		.2
Pension plans		.4			.4			1.3			1.1
OPEB plans		(.1	)		(.1	)		(.2	)		(.1	)

Total	$	4.5		$	7.3		$	6.6		$	30.5

Accumulated Other Comprehensive Income (Loss) (Tables)

9 Months Ended

Sep. 30, 2017

Stockholders Equity Note [Abstract]

Schedule of Changes in Accumulated Other Comprehensive Income (Loss)

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2017			2016			2017

Accumulated other comprehensive loss, net of tax:
Marketable securities:
Balance at beginning of period	$	2,394		$	15,882		$	195		$	20,473
Other comprehensive income (loss) - unrealized gains (losses) arising during the year		6,983			(5,260	)		9,182			(9,851	)

Balance at end of period	$	9,377		$	10,622		$	9,377		$	10,622

Currency translation:
Balance at beginning of period	$	(170,533	)	$	(171,163	)	$	(172,384	)	$	(175,859	)
Other comprehensive income		1,777			5,908			3,628			10,604

Balance at end of period	$	(168,756	)	$	(165,255	)	$	(168,756	)	$	(165,255	)

Interest rate swap:
Balance at beginning of period	$	(1,173	)	$	(362	)	$	(445	)	$	(390	)
Other comprehensive income (loss):
Unrealized gains (losses) arising during the year		32			(119	)		(920	)		(296	)
Less reclassification adjustment for amounts included in interest expense		113			481			337			686

Balance at end of period	$	(1,028	)	$	-		$	(1,028	)	$	-

Defined benefit pension plans:
Balance at beginning of period	$	(71,082	)	$	(75,450	)	$	(72,712	)	$	(76,710	)
Other comprehensive income - amortization of net losses included in net periodic pension cost		817			738			2,447			1,998

Balance at end of period	$	(70,265	)	$	(74,712	)	$	(70,265	)	$	(74,712	)

OPEB plans:
Balance at beginning of period	$	(276	)	$	(456	)	$	(12	)	$	(360	)
Other comprehensive loss - amortization of prior service credit and net gains included in net periodic OPEB cost		(132	)		(49	)		(396	)		(145	)

Balance at end of period	$	(408	)	$	(505	)	$	(408	)	$	(505	)

Total accumulated other comprehensive loss:
Balance at beginning of period	$	(240,670	)	$	(231,549	)	$	(245,358	)	$	(232,846	)
Other comprehensive income		9,590			1,699			14,278			2,996

Balance at end of period	$	(231,080	)	$	(229,850	)	$	(231,080	)	$	(229,850	)

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2017

Commitments And Contingencies Disclosure [Abstract]

Changes in Accrued Environmental Remediation and Related Costs

Changes in the accrued environmental remediation and related costs during the first nine months of 2017 are as follows:

	Amount
	(In thousands)
Balance at the beginning of the period	$	116,658
Additions charged to expense, net		3,236
Payments, net		(4,628	)

Balance at the end of the period	$	115,266

Amounts recognized in the Condensed Consolidated
Balance Sheet at the end of the period:
Current liability	$	11,400
Noncurrent liability		103,866

Balance at the end of the period	$	115,266

Financial Instruments and Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Summary of Financial Instruments Not Carried at Fair Value

The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure:

	December 31, 2016				September 30, 2017
	Carrying		Fair		Carrying		Fair
	amount		value		amount		value
	(In thousands)
Cash, cash equivalents and restricted cash	$	98,242	$	98,242	$	101,760	$	101,760
Noncontrolling interest in CompX common stock		16,350		26,790		17,284		25,483

Organization and Basis of Presentation - Additional Information (Detail)	Sep. 30, 2017
Kronos
Organization And Basis Of Presentation [Line Items]
Parent company ownership interest	30.00%
Valhi Inc
Organization And Basis Of Presentation [Line Items]
Parent company ownership interest	83.00%
Valhi Inc \| Contran Corporation
Organization And Basis Of Presentation [Line Items]
Parent company ownership interest	93.00%

Accounts and Other Receivables, Net - Schedule of Accounts Notes Loans and Financing Receivable (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Accrued insurance recoveries	$ 139	$ 104
Other receivables	139	135
Total	11,995	10,586
CompX
Receivables [Abstract]
Trade receivables	11,787	10,417
Allowance for doubtful accounts	$ (70)	$ (70)

Inventories, Net - Schedule of Inventories, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 2,867	$ 2,743
Work in process	9,684	8,988
Finished products	2,762	3,243
Total	$ 15,313	$ 14,974

Marketable Securities - Schedule of Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Market value	$ 34,926	$ 49,731
Level 1 \| Valhi Inc \| Common stock
Schedule Of Available For Sale Securities [Line Items]
Market value	34,926	49,731
Cost basis	24,347	24,347
Unrealized gain	$ 10,579	$ 25,384

Marketable Securities - Additional Information (Detail) - Valhi Inc - Common stock - $ / shares shares in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Number of shares owned	14.4	14.4
Quoted marked price per share	$ 2.43	$ 3.46

Investment in Kronos Worldwide, Inc. - Additional Information (Detail) - Kronos - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Equity Method Investments [Line Items]
Number of shares owned	35.2	35.2
Aggregate market value	$ 804.1	$ 420.5
Quoted market price per share	$ 22.83	$ 11.94

Investment in Kronos Worldwide, Inc. - Changes in Carrying Value of Investment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Balance at the beginning of the period			$ 120,346
Equity in earnings of Kronos	$ 22,437	$ 6,776	93,357	$ 6,123
Dividends received from Kronos			(15,849)	$ (15,849)
Equity in Kronos' other comprehensive income (loss):
Balance at the end of the period	216,301		216,301
Kronos
Balance at the beginning of the period			120,300
Equity in earnings of Kronos			93,400
Dividends received from Kronos			(15,800)
Equity in Kronos' other comprehensive income (loss):
Marketable securities			(400)
Currency translation			16,300
Interest rate swap			600
Balance at the end of the period	$ 216,300		216,300
Kronos \| Defined Benefit Pension Plans
Equity in Kronos' other comprehensive income (loss):
Defined benefit pension plans			$ 1,900

Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Balance Sheet (Detail) - Kronos - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,021.2	$ 650.4
Property and equipment, net	486.2	434.0
Investment in TiO2 joint venture	75.1	78.9
Deferred income taxes	120.0	8.1
Other noncurrent assets	7.9	8.2
Total assets	1,710.4	1,179.6
Current liabilities	240.0	182.1
Long-term debt	467.5	335.4
Accrued pension and postretirement benefits	261.6	234.2
Other noncurrent liabilities	30.6	32.9
Stockholders' equity	710.7	395.0
Total liabilities and stockholders' equity	$ 1,710.4	$ 1,179.6

Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Income Statement (Detail) - Kronos - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule Of Equity Method Investments [Line Items]
Net sales	$ 464.5	$ 356.1	$ 1,275.7	$ 1,030.6
Cost of sales	312.3	280.6	890.3	859.2
Income from operations	91.6	28.0	214.0	38.2
Income tax expense (benefit)	6.1	0.7	(114.0)	3.2
Net income	$ 73.8	$ 22.2	$ 307.1	$ 20.1

Other Noncurrent Assets, Net - Summary of Other Noncurrent Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Restricted cash	$ 1,264	$ 1,289
Pension asset	1,342	1,037
Other	964	950
Total	$ 3,570	$ 3,276

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Employee benefits	$ 7,793	$ 8,375
Professional fees	555	613
Other	1,617	1,636
Total	$ 9,965	$ 10,624

Long-Term Debt - Additional Information (Detail) - NLKW Holding, LLC - Valhi - Valhi Credit Facility	9 Months Ended
	Sep. 30, 2017 USD ($)
Debt Instrument [Line Items]
Maximum borrowing under credit facility	$ 50,000,000
Borrowings or repayments under revolving credit facility	0
Outstanding borrowing	500,000
Remaining future borrowing under revolving credit facility	$ 49,500,000
Debt instrument, description of variable rate basis	prime rate
Variable rate basis spread above reference rate	1.875%
Debt instrument average interest rate	6.125%
Debt instrument average interest rate, during period	5.90%

Employee Benefit Plans - Components of Net Periodic Defined Benefit Cost (Income) (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 506,000	$ 585,000	$ 1,518,000	$ 1,778,000
Expected return on plan assets	(689,000)	(723,000)	(2,067,000)	(2,194,000)
Recognized actuarial (gains) losses	394,000	406,000	1,182,000	1,314,000
Total	211,000	268,000	633,000	898,000	$ 865,000
OPEB
Defined Benefit Plan Disclosure [Line Items]
Interest cost	20,000	24,000	60,000	72,000
Amortization of prior service credit		(135,000)		(406,000)
Recognized actuarial (gains) losses	(54,000)	(38,000)	(162,000)	(114,000)
Total	$ (34,000)	$ (149,000)	$ (102,000)	$ (448,000)	$ (597,000)

Employee Benefit Plans - Additional Information (Detail) $ in Millions	Sep. 30, 2017 USD ($)
Defined Benefit Pension Plans and Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Expected contribution during 2017	$ 1.4

Other Noncurrent Liabilities - Summary of Other Noncurrent Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Reserve for uncertain tax positions	$ 12,186	$ 12,186
Insurance claims and expenses	643	589
Other	673	767
Total	$ 13,502	$ 13,542

Income Taxes - Component of Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Expected tax expense, at U.S. federal statutory income tax rate of 35%	$ 8,500	$ 2,500	$ 34,000	$ 2,000
Rate differences on equity in earnings of Kronos	(2,100)	(3,000)	(5,000)	(2,800)
Nontaxable income	(100)	(200)	(300)	(400)
U.S. state income taxes and other, net	200	100	200	100
Income tax expense (benefit)	$ 6,466	$ (560)	$ 28,923	$ (1,052)

Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Comprehensive provision for income taxes (benefit) allocable to:
Net income	$ 6,466	$ (560)	$ 28,923	$ (1,052)
Other comprehensive income (loss):
Marketable securities	(2,800)	3,700	(5,300)	4,900
Currency translation	3,100	1,000	5,700	2,000
Interest rate swap	200	100	200	(300)
Total	7,300	4,500	30,500	6,600
Defined Benefit Pension Plans
Other comprehensive income (loss):
Defined benefit plans	400	400	1,100	1,300
OPEB
Other comprehensive income (loss):
Defined benefit plans	$ (100)	$ (100)	$ (100)	$ (200)

Income Taxes - Component of Income Taxes (Parenthetical) (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%	35.00%

Income Taxes - Additional Information (Detail) CAD in Millions		3 Months Ended			6 Months Ended	9 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2017 CAD	Sep. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.						$ 15,849,000	$ 15,849,000
Income tax benefit		$ (6,466,000)		$ 560,000		(28,923,000)	1,052,000
Kronos
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.						15,800,000	$ 15,800,000
Deferred income tax asset valuation allowance									$ 0
Estimated reversal of deferred income tax asset valuation allowance		11,700,000				$ 11,700,000
Kronos \| US-Canada APA
Income Tax Disclosure [Line Items]
U.S.-Canada Advance Pricing Agreement, description						During the third quarter of 2016, Contran, as the ultimate parent of Kronos’ U.S. Consolidated income tax group, executed and finalized an Advance Pricing Agreement with the U.S. Internal Revenue Service and Kronos’ Canadian subsidiary executed and finalized an Advance Pricing Agreement with the Competent Authority for Canada (collectively, the “U.S.-Canada APA”) effective for tax years 2005 - 2015.
Current U.S. income tax benefit				$ (5,600,000)
Kronos \| US-Canada APA \| Earliest Tax Year \| Canada Revenue Agency
Income Tax Disclosure [Line Items]
Effective tax year				2005
Kronos \| US-Canada APA \| Latest Tax Year \| Canada Revenue Agency
Income Tax Disclosure [Line Items]
Effective tax year				2015
Kronos \| Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	$ (149,900,000)
Kronos \| Effect of Currency Exchange Rates
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance						$ 9,000,000
Kronos \| Germany
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance								$ 153,000,000
Kronos \| Germany \| Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	(141,900,000)
Kronos \| Germany \| Corporate Tax Purposes
Income Tax Disclosure [Line Items]
Net operating loss carryforwards								638,000,000
Kronos \| Germany \| Trade Tax Purposes
Income Tax Disclosure [Line Items]
Net operating loss carryforwards								71,000,000
Kronos \| Belgium
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance								20,000,000
Kronos \| Belgium \| Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	$ (8,000,000)
Kronos \| Belgium \| Corporate Tax Purposes
Income Tax Disclosure [Line Items]
Net operating loss carryforwards								93,000,000
Kronos \| Germany and Belgian
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance								173,000,000
Increase (decrease) in non-cash deferred income tax asset valuation allowance						$ (170,400,000)
Kronos \| Germany and Belgian \| Current Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance		(7,800,000)			$ (12,700,000)			$ (2,200,000)
Kronos Canadian Subsidiary \| US-Canada APA
Income Tax Disclosure [Line Items]
Income tax paid		$ 2,300,000	CAD 3
Kronos Canadian Subsidiary \| Canada-Germany APA \| Earliest Tax Year \| Canada Revenue Agency
Income Tax Disclosure [Line Items]
Effective tax year		2005	2005
Kronos Canadian Subsidiary \| Canada-Germany APA \| Latest Tax Year \| Canada Revenue Agency
Income Tax Disclosure [Line Items]
Effective tax year		2017	2017
Kronos Canadian And German Subsidiaries \| Canada-Germany APA \| Canada Revenue Agency and German Federal Central Tax Office
Income Tax Disclosure [Line Items]
Income tax benefit		$ 11,300,000
Non-cash income tax benefit related to reversal of reserve for uncertain tax positions		8,100,000
Kronos Canadian And German Subsidiaries \| Germany \| Canada-Germany APA \| Canada Revenue Agency and German Federal Central Tax Office
Income Tax Disclosure [Line Items]
Non-cash income tax benefit related to increase in German NOLs		2,600,000
Cash tax refund		$ 600,000

Accumulated Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period			$ 177,920,000
Other comprehensive income (loss)	$ 1,699	$ 9,590	2,996	$ 14,278
Balance at end of period	248,100,000		248,100,000
Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	15,882	2,394	20,473	195
Other comprehensive income (loss)	(5,260)	6,983	(9,851)	9,182
Balance at end of period	10,622	9,377	10,622	9,377
Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(171,163)	(170,533)	(175,859)	(172,384)
Other comprehensive income (loss)	5,908	1,777	10,604	3,628
Balance at end of period	(165,255)	(168,756)	(165,255)	(168,756)
Interest Rate Swap
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(362)	(1,173)	(390)	(445)
Other comprehensive income (loss)	(119)	32	(296)	(920)
Less reclassification adjustment for amounts included in interest expense	481	113	686	337
Balance at end of period		(1,028)		(1,028)
Accumulated Defined Benefit Plans Adjustment \| Defined Benefit Pension Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(75,450)	(71,082)	(76,710)	(72,712)
Other comprehensive income (loss)	738	817	1,998	2,447
Balance at end of period	(74,712)	(70,265)	(74,712)	(70,265)
Accumulated Defined Benefit Plans Adjustment \| OPEB
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(456)	(276)	(360)	(12)
Other comprehensive income (loss)	(49)	(132)	(145)	(396)
Balance at end of period	(505)	(408)	(505)	(408)
Total Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(231,549)	(240,670)	(232,846)	(245,358)
Balance at end of period	$ (229,850)	$ (231,080)	$ (229,850)	$ (231,080)

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	9 Months Ended
	Jan. 31, 2014 USD ($)	Sep. 30, 2017 USD ($) Cases site Plaintiff	Dec. 31, 2016 USD ($)
Commitments and Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters		$ 115,266,000	$ 116,658,000
Environmental Remediation Sites NL Named As PRP Or Defendant
Commitments and Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters		$ 115,000,000
Number of sites associated with remediation and related costs \| site		38
Number of sites currently not able to reasonably estimate a range of costs \| site		5
Maximum \| Environmental Remediation Sites NL Named As PRP Or Defendant
Commitments and Contingent Liabilities [Line Items]
Upper end range, estimate costs for remediation and related matters		$ 157,000,000
Environmental Remediation Litigation
Commitments and Contingent Liabilities [Line Items]
Recoveries receivable		$ 0	$ 0
Lead Pigment Litigation
Commitments and Contingent Liabilities [Line Items]
Number of cases settled and dismissed and found not liable \| Cases		100
Period by which loss contingency claims settled and dismissed		20 years
California Lead Paint Litigation
Commitments and Contingent Liabilities [Line Items]
Amount awarded to the plaintiff	$ 1,150,000,000
Product Liability And Occupational Exposure Litigation Claims
Commitments and Contingent Liabilities [Line Items]
Number of cases pending \| Cases		103
Product Liability And Occupational Exposure Litigation Claims \| Administratively Dismissed Claims
Commitments and Contingent Liabilities [Line Items]
Number of plaintiffs involved \| Plaintiff		8,680
Product Liability And Occupational Exposure Litigation Claims \| Pending Claims
Commitments and Contingent Liabilities [Line Items]
Number of plaintiffs involved \| Plaintiff		587

Commitments and Contingencies - Changes in Accrued Environmental Remediation and Related Costs (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Balance at the beginning of the period	$ 116,658
Additions charged to expense, net	3,236
Payments, net	(4,628)
Balance at the end of the period	115,266
Amounts recognized in the Condensed Consolidated Balance Sheet at the end of the period:
Current liability		$ 11,400	$ 13,350
Noncurrent liability		103,866	103,308
Balance at the end of the period	$ 116,658	$ 115,266	$ 116,658

Financial Instruments and Fair Value Measurements - Summary of Financial Instruments Not Carried at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash, Carrying amount	$ 101,760	$ 98,242	$ 105,610	$ 100,981
Cash, cash equivalents and restricted cash, Fair value	101,760	98,242
Noncontrolling interest in subsidiary	17,284	16,350
Carrying amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash, Carrying amount	101,760	98,242
Carrying amount \| CompX
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Noncontrolling interest in subsidiary	17,284	16,350
Fair Value \| CompX
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Noncontrolling interest in subsidiary	$ 25,483	$ 26,790

Recent Accounting Pronouncements - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Net periodic cost (credit)	$ 211,000	$ 268,000	$ 633,000	$ 898,000	$ 865,000
OPEB
Defined Benefit Plan Disclosure [Line Items]
Net periodic cost (credit)	$ (34,000)	$ (149,000)	$ (102,000)	$ (448,000)	$ (597,000)