Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Net Sales	$ 719,185	$ 602,688	$ 2,146,094	$ 1,735,939
Cost of Sales	600,709	510,792	1,786,785	1,423,382
Gross Profit	118,476	91,896	359,309	312,557
Operating Expenses:
Selling	15,079	14,786	45,908	44,280
Administrative	33,848	22,828	79,499	69,440
Research, development and technical services	16,929	15,501	50,092	45,638
Deferred compensation (income) expense	(2,131)	(1,504)	(13,038)	2,148
Total Operating expenses	63,725	51,611	162,461	161,506
Goodwill impairment (Note 18)			(978)
Business restructuring expenses (Note 16)	(92)	(72)	(225)	(267)
Operating Income	54,659	40,213	195,645	150,784
Other Income (Expense):
Interest, net	(2,221)	(1,599)	(7,254)	(4,690)
Other, net (Note 15)	(1,980)	702	(8,999)	4,206
Nonoperating Income (Expense), Total	(4,201)	(897)	(16,253)	(484)
Income Before Provision for Income Taxes	50,458	39,316	179,392	150,300
Provision for Income Taxes	11,074	2,393	43,073	29,463
Net Income	39,384	36,923	136,319	120,837
Less: Net Income Attributable to Noncontrolling Interest		(3)		28
Net Income Attributable to Stepan Company	$ 39,384	$ 36,920	$ 136,319	$ 120,809
Net Income Per Common Share Attributable to Stepan Company (Note 10):
Basic	$ 1.73	$ 1.61	$ 5.98	$ 5.27
Diluted	$ 1.71	$ 1.59	$ 5.90	$ 5.19
Shares Used to Compute Net Income Per Common Share Attributable to Stepan Company (Note 10):
Basic	22,753	22,898	22,813	22,941
Diluted	23,034	23,219	23,089	23,299