Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	SCL
Entity Registrant Name	STEPAN COMPANY
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Central Index Key	0000094049
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Tax Identification Number	36-1823834
Entity File Number	1-4462
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	22 West Frontage Road
Entity Address, City or Town	Northfield
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60093
City Area Code	847
Local Phone Number	446-7500
Security Exchange Name	NYSE
Title of 12(b) Security	Common Stock, $1 par value
Document Annual Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		22,516,988
Entity Public Float			$ 1,862,119,945