CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income (loss)	$ 1,165	$ (28,900)	$ (1,016)	$ (18,543)
Other comprehensive income (loss), net of tax:
Marketable securities	3,730	(5,358)	2,199	(7,144)
Currency translation	(980)	1,188	1,851	(11,771)
Interest rate swap	(157)		(728)
Total other comprehensive income (loss), net	3,284	(3,220)	4,688	(17,367)
Comprehensive income (loss)	4,449	(32,120)	3,672	(35,910)
Comprehensive income attributable to noncontrolling interest	320	367	608	682
Comprehensive income (loss) attributable to NL stockholders	4,129	(32,487)	3,064	(36,592)
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	823	1,087	1,630	1,821
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	$ (132)	$ (137)	$ (264)	$ (273)