Consolidated Statements of Income - USD ($) shares in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net Sales (Note 1)	[1]	$ 2,345,966,000	$ 1,869,750,000	$ 1,858,745,000
Cost of Sales		1,950,156,000	1,486,137,000	1,519,031,000
Gross Profit		395,810,000	383,613,000	339,714,000
Operating Expenses:
Selling (Note 1)		59,186,000	55,543,000	56,956,000
Administrative (Note 1)		92,906,000	87,362,000	82,577,000
Research, development and technical services (Note 1)		62,689,000	57,986,000	55,037,000
Deferred compensation expense (Note 12)		6,895,000	9,988,000	15,140,000
Total Operating expenses		221,676,000	210,879,000	209,710,000
Business restructuring and loss on asset disposition (Note 22)		(3,353,000)	(1,212,000)	(2,744,000)
Operating Income		170,781,000	171,522,000	127,260,000
Other Income (Expense):
Interest, net (Note 6)		(5,753,000)	(5,409,000)	(5,932,000)
Other, net (Note 8)		7,509,000	4,954,000	4,571,000
Nonoperating Income (Expense), Total		1,756,000	(455,000)	(1,361,000)
Income Before Provision for Income Taxes		172,537,000	171,067,000	125,899,000
Provision for Income Taxes (Note 9)		34,642,000	43,411,000	22,798,000
Net Income		137,895,000	127,656,000	103,101,000
Net (Income) Loss Attributable to Noncontrolling Interest (Note 1)		(91,000)	(886,000)	28,000
Net Income Attributable to Stepan Company		$ 137,804,000	$ 126,770,000	$ 103,129,000
Net Income Per Common Share Attributable to Stepan Company (Note 18):
Basic		$ 6.01	$ 5.52	$ 4.47
Diluted		$ 5.92	$ 5.45	$ 4.42
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 18):
Basic		22,922	22,949	23,054
Diluted		23,287	23,256	23,316

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