Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net Sales		$ 468,269	$ 445,897
Cost of Sales		376,171	352,398
Gross Profit		92,098	93,499
Operating Expenses:
Selling		13,485	13,690
Administrative		17,971	18,700
Research, development and technical services		13,421	13,782
Deferred compensation expense		376	2,720
Total Operating expenses		45,253	48,892
Business restructuring expenses (Note 14)		786
Operating Income		46,059	44,607
Other Income (Expense):
Interest, net		(2,992)	(3,614)
Other, net (Note 13)		1,263	(525)
Nonoperating Income (Expense), Total		(1,729)	(4,139)
Income Before Provision for Income Taxes		44,330	40,468
Provision for Income Taxes	[1]	12,418	12,549
Net Income	[1]	31,912	27,919	[2]
Net (Income) Loss Attributable to Noncontrolling Interests (Note 2)		1	(3)
Net Income Attributable to Stepan Company(a)	[1]	$ 31,913	$ 27,916
Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic	[1]	$ 1.39	$ 1.23
Diluted	[1]	$ 1.37	$ 1.22
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 9):
Basic		22,901	22,733
Diluted	[1]	23,331	22,899
Dividends Declared Per Common Share		$ 0.21	$ 0.19

[1] The 2016 amounts for the noted line items have been immaterially changed from the amounts originally reported as a result of the Company’s fourth quarter 2016 adoption of Accounting Standards Update (ASU) No. 2019-9, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.

[2] Amounts for the noted line items have been immaterially changed from the amounts originally reported as a result of the Company’s fourth quarter 2016 adoption of ASU No. 2016-9, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.