CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net income (loss)	$ 16,693	$ (22,716)	$ 29,630
Other comprehensive income (loss), net of tax:
Marketable securities	20,278	(46,917)	(107,057)
Currency translation	(3,475)	(18,211)	(20,357)
Interest rate swap	55	(445)
Total other comprehensive income (loss), net	12,512	(63,319)	(147,023)
Comprehensive income (loss)	29,205	(86,035)	(117,393)
Comprehensive income attributable to noncontrolling interest	1,368	1,193	1,131
Comprehensive income (loss) attributable to NL stockholders	27,837	(87,228)	(118,524)
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	(3,998)	2,548	(18,616)
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	$ (348)	$ (294)	$ (993)