CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income (loss)	$ 14,180	$ (5,684)	$ 24,020	$ (21,700)
Other comprehensive income (loss), net of tax:
Marketable securities	1,022	59,716	(105,842)	71,542
Currency translation	(9,215)	4,155	(10,589)	(119)
Total other comprehensive income (loss), net	(7,819)	64,419	(115,315)	73,069
Comprehensive income (loss)	6,361	58,735	(91,295)	51,369
Comprehensive income attributable to noncontrolling interest	291	256	904	613
Comprehensive income (loss) attributable to NL stockholders	6,070	58,479	(92,199)	50,756
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	530	692	1,585	2,078
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit pension plans/ Other postretirement benefit plans	$ (156)	$ (144)	$ (469)	$ (432)