Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 16,941	$ 24,368	$ 38,227	$ 37,376
Other comprehensive income (loss):
Foreign currency translation adjustments (Note 10)	5,957	3,718	(19,195)	3,812
Pension liability adjustment, net of tax (Note 10)	750	410	1,499	820
Derivative instrument activity, net of tax (Note 10)	16	1	(26)	4
Other comprehensive income (loss)	6,723	4,129	(17,722)	4,636
Comprehensive income	23,664	28,497	20,505	42,012
Comprehensive (income) loss attributable to noncontrolling interests (Note 2)	(44)	9	(45)	42
Comprehensive income attributable to Stepan Company	$ 23,620	$ 28,506	$ 20,460	$ 42,054