Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 01, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	000-22117
Entity Registrant Name	SILGAN HOLDINGS INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-1269834
Entity Address, Address Line One	4 Landmark Square
Entity Address, City or Town	Stamford,
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06901
City Area Code	203
Local Phone Number	975-7110
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	SLGN
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3,470
Entity Common Stock, Shares Outstanding		110,410,229
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0000849869
Current Fiscal Year End Date	--12-31