Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 27,870	$ 16,941	$ 55,527	$ 38,227
Other comprehensive income (loss):
Foreign currency translation adjustments (Note 10)	(2,692)	5,957	9,898	(19,195)
Pension liability adjustment, net of tax (Note 10)	565	750	1,129	1,499
Derivative instrument activity, net of tax (Note 10)	(6)	16	(27)	(26)
Other comprehensive income (loss)	(2,133)	6,723	11,000	(17,722)
Comprehensive income	25,737	23,664	66,527	20,505
Comprehensive (income) loss attributable to noncontrolling interests (Note 2)	39	(44)	25	(45)
Comprehensive income attributable to Stepan Company	$ 25,776	$ 23,620	$ 66,552	$ 20,460