Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net Sales (Note 1)	[1]	$ 1,766,166		$ 1,776,167	$ 1,927,213
Cost of Sales		1,427,621		1,467,926	1,677,650
Gross Profit		338,545		308,241	249,563
Operating Expenses:
Selling (Note 1)		57,212		55,522	54,763
Administrative (Note 1)		75,185		76,048	66,549
Research, development and technical services (Note 1)		56,086		50,243	45,451
Deferred compensation expense (income)		16,805		6,500	(11,903)
Total Operating expenses		205,288		188,313	154,860
Gain on sale of product line				2,862
Business restructuring and asset impairments (Note 22)		(7,064)			(4,009)
Operating Income		126,193		122,790	90,694
Other Income (Expense):
Interest, net (Note 6)		(13,205)		(14,533)	(11,441)
Loss from equity in joint ventures (Notes 1 and 25)				(6,985)	(5,008)
Other, net (Note 8)		828		1,584	1,290
Nonoperating Income (Expense), Total		(12,377)		(19,934)	(15,159)
Income Before Provision for Income Taxes		113,816		102,856	75,535
Provision for Income Taxes (Note 9)		27,618		26,819	18,454
Net Income		86,198	[2]	76,037	57,081
Net (Income) Loss Attributable to Noncontrolling Interests (Note 1)		(7)		(69)	20
Net Income Attributable to Stepan Company		$ 86,191	[2]	$ 75,968	$ 57,101
Net Income Per Common Share Attributable to Stepan Company (Note 18):
Basic		$ 3.78		$ 3.34	$ 2.51
Diluted		$ 3.73	[2]	$ 3.32	$ 2.49
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 18):
Basic		22,793		22,730	22,758
Diluted		23,094		22,858	22,917

[1] Net sales are attributed to countries based on the location of the Company facility making the sales.

[2] The amounts for net income, net income attributable to Stepan Company and net income attributable to Stepan Company per diluted share for the first, second and third quarters of 2016 have been changed from the amounts originally reported as a result of the Company’s early adoption of ASU No. 2016-9, Compensation – Stock Compensation (Topic 718): Improvement to Employee Share-Based Payment Accounting. See Note 1 for additional information regarding ASU No. 2016-9. Below are the originally reported amounts for the items that changed: 2016 (In thousands, except per share data) First Second Third Net Income $27,657 $27,870 $20,432 Net Income Attributable to Stepan Company 27,654 27,865 20,427 Per Diluted Share 1.21 1.21 0.89