Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 24,934	$ 13,480	$ 63,161	$ 50,856
Other comprehensive income (loss):
Foreign currency translation adjustments (Note 10)	(19,793)	(19,521)	(38,988)	(15,709)
Pension liability adjustment, net of tax (Note 10)	722	429	2,221	1,249
Derivative instrument activity, net of tax (Note 10)	(14)	2	(40)	6
Total other comprehensive loss	(19,085)	(19,090)	(36,807)	(14,454)
Comprehensive income	5,849	(5,610)	26,354	36,402
Comprehensive (income) loss attributable to noncontrolling interests (Note 2)	21	(14)	(24)	28
Comprehensive income (loss) attributable to Stepan Company	$ 5,870	$ (5,624)	$ 26,330	$ 36,430