CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income (loss)	$ 41,598	$ 1,165	$ 50,360	$ (1,016)
Other comprehensive income (loss), net of tax:
Marketable securities	(2,869)	3,730	(4,591)	2,199
Currency translation	2,925	(980)	4,696	1,851
Interest rate swap	(84)	(157)	28	(728)
Total other comprehensive income, net	317	3,284	1,297	4,688
Comprehensive income	41,915	4,449	51,657	3,672
Comprehensive income attributable to noncontrolling interest	431	320	843	608
Comprehensive income attributable to NL stockholders	41,484	4,129	50,814	3,064
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	393	823	1,260	1,630
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	$ (48)	$ (132)	$ (96)	$ (264)