CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 15,726	$ 14,735
Other comprehensive income (loss), net of tax:
Currency translation	(25)	2,591
Defined benefit pension plans	828	983
Other	(70)	(73)
Total other comprehensive income, net	733	3,501
Comprehensive income	16,459	18,236
Comprehensive income attributable to noncontrolling interest	522	487
Comprehensive income attributable to NL stockholders	$ 15,937	$ 17,749

Other comprehensive income (loss), other net of tax.

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Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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