Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net Sales	$ 675,276	$ 537,740
Cost of Sales	566,057	428,760
Gross Profit	109,219	108,980
Operating Expenses:
Selling	15,277	14,504
Administrative	21,572	22,638
Research, development and technical services	16,473	15,149
Deferred compensation (income) expense	(7,501)	2,694
Total Operating expenses	45,821	54,985
Business restructuring expenses (Note 16)	(52)	(81)
Operating Income	63,346	53,914
Other Income (Expense):
Interest, net	(2,306)	(1,524)
Other, net (Note 15)	(1,650)	746
Nonoperating Income (Expense), Total	(3,956)	(778)
Income Before Provision for Income Taxes	59,390	53,136
Provision for Income Taxes	14,581	12,525
Net Income	44,809	40,611
Net Income Attributable to Stepan Company	$ 44,809	$ 40,611
Net Income Per Common Share Attributable to Stepan Company (Note 10):
Basic	$ 1.96	$ 1.77
Diluted	$ 1.93	$ 1.74
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 10):
Basic	22,896	22,974
Diluted	23,167	23,330