Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net Sales		$ 454,603	$ 452,414	$ 900,500	$ 912,865
Cost of Sales		361,672	372,902	714,070	756,911
Gross Profit		92,931	79,512	186,430	155,954
Operating Expenses:
Selling		14,572	14,265	28,262	27,262
Administrative	[1]	17,692	17,482	36,392	35,244
Research, development and technical services		14,256	12,597	28,038	24,387
Deferred compensation expense	[1]	2,434	6,573	5,154	8,150
Total Operating expenses		48,954	50,917	97,846	95,043
Gain on sale of product line					2,862
Business restructuring		(1,061)		(1,061)
Operating Income		42,916	28,595	87,523	63,773
Other Income (Expense):
Interest, net		(3,417)	(2,869)	(7,031)	(6,923)
Loss from equity in joint ventures (Note 16)			(1,815)		(3,055)
Other, net (Note 13)		(303)	235	(828)	887
Nonoperating Income (Expense), Total		(3,720)	(4,449)	(7,859)	(9,091)
Income Before Provision for Income Taxes		39,196	24,146	79,664	54,682
Provision for Income Taxes		11,326	7,205	24,137	16,455
Net Income		27,870	16,941	55,527	38,227
Net Income Attributable to Noncontrolling Interests (Note 2)		(5)	(27)	(8)	(43)
Net Income Attributable to Stepan Company		$ 27,865	$ 16,914	$ 55,519	$ 38,184
Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic		$ 1.22	$ 0.74	$ 2.44	$ 1.68
Diluted		$ 1.21	$ 0.74	$ 2.42	$ 1.67
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic		22,760	22,742	22,746	22,731
Diluted		22,958	22,871	22,920	22,850
Dividends Declared Per Common Share		$ 0.19	$ 0.18	$ 0.38	$ 0.36

[1] For the three and six months ended June 30, 2015, deferred compensation expense was included in the administrative expense line. The 2015 amounts have been classified separately to conform to the current year presentation.