Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 20,432	$ 24,934	$ 75,959	$ 63,161
Other comprehensive income (loss):
Foreign currency translation adjustments (Note 10)	(2,213)	(19,793)	7,685	(38,988)
Pension liability adjustment, net of tax (Note 10)	497	722	1,626	2,221
Derivative instrument activity, net of tax (Note 10)		(14)	(27)	(40)
Other comprehensive income (loss)	(1,716)	(19,085)	9,284	(36,807)
Comprehensive income	18,716	5,849	85,243	26,354
Comprehensive (income) loss attributable to noncontrolling interests (Note 2)	(1)	21	24	(24)
Comprehensive income attributable to Stepan Company	$ 18,715	$ 5,870	$ 85,267	$ 26,330