Reconciliations of Equity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Reconciliations of total equity
Beginning Balance			$ 405,465	$ 353,071
Stockholders' Equity, Beginning Balance			401,211
Noncontrolling Interests' , Beginning Balance			4,254
Net income	21,511	21,006	43,875	39,822
Net income, Stepan Company Equity	21,425	20,867	43,727	39,628
Net income, Noncontrolling Interests'	86	139	148	194
Purchase of remaining interest in Stepan Philippines, Inc. from noncontrolling interest			(2,000)
Dividends			(6,148)	(5,638)
Common stock purchases			(1,761)	(2,274)
Stock option exercises			2,320	889
Defined benefit pension adjustments, net of tax	582	521	1,164	1,044
Translation adjustments	(10,554)	3,964	(2,020)	10,081
Derivative instrument activity, net of tax	(43)	315	64	389
Other			3,908	3,603
Ending Balance	444,867	400,987	444,867	400,987
Stockholders' Equity, Ending Balance	443,159		443,159
Noncontrolling Interests' , Ending Balance	1,708		1,708
Noncontrolling Interest's Equity [Member]
Reconciliations of total equity
Noncontrolling Interests' , Beginning Balance			4,254	3,580
Net income, Noncontrolling Interests'			148	194
Purchase of remaining interest in Stepan Philippines, Inc. from noncontrolling interest			(2,748)
Dividends
Common stock purchases
Stock option exercises
Defined benefit pension adjustments, net of tax
Translation adjustments, Noncontrolling Interests'			54	42
Derivative instrument activity, net of tax
Other
Noncontrolling Interests' , Ending Balance	1,708	3,816	1,708	3,816
Stepan Company Equity [Member]
Reconciliations of total equity
Stockholders' Equity, Beginning Balance			401,211	349,491
Net income, Stepan Company Equity			43,727	39,628
Purchase of remaining interest in Stepan Philippines, Inc. from noncontrolling interest			748
Dividends			(6,148)	(5,638)
Common stock purchases			(1,761)	(2,274)
Stock option exercises			2,320	889
Defined benefit pension adjustments, net of tax			1,164	1,044
Translation adjustments, Stepan Company Equity			(2,074)	10,039
Derivative instrument activity, net of tax			64	389
Other			3,908	3,603
Stockholders' Equity, Ending Balance	$ 443,159	$ 397,171	$ 443,159	$ 397,171