Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net Sales	$ 452,414	$ 504,111	$ 912,865	$ 981,553
Cost of Sales	372,902	432,522	756,911	846,940
Gross Profit	79,512	71,589	155,954	134,613
Operating Expenses:
Selling	14,265	13,493	27,262	27,639
Administrative	24,055	9,052	43,394	23,483
Research, development and technical services	12,597	12,130	24,387	24,054
Total Operating expenses	50,917	34,675	95,043	75,176
Gain on sale of product line			2,862
Operating Income	28,595	36,914	63,773	59,437
Other Income (Expense):
Interest, net	(2,869)	(3,021)	(6,923)	(5,978)
Loss from equity in joint ventures	(1,815)	(1,243)	(3,055)	(2,694)
Other, net (Note 13)	235	556	887	530
Nonoperating Income (Expense), Total	(4,449)	(3,708)	(9,091)	(8,142)
Income Before Provision for Income Taxes	24,146	33,206	54,682	51,295
Provision for Income Taxes	7,205	8,838	16,455	13,919
Net Income	16,941	24,368	38,227	37,376
Net Income Attributable to Noncontrolling Interests (Note 2)	(27)	(15)	(43)	(5)
Net Income Attributable to Stepan Company	$ 16,914	$ 24,353	$ 38,184	$ 37,371
Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic	$ 0.74	$ 1.07	$ 1.68	$ 1.64
Diluted	$ 0.74	$ 1.06	$ 1.67	$ 1.63
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic	22,742	22,763	22,731	22,768
Diluted	22,871	22,931	22,850	22,948
Dividends Declared Per Common Share	$ 0.18	$ 0.17	$ 0.36	$ 0.34