Cover - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-12139
Entity Registrant Name	SEALED AIR CORP/DE
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	65-0654331
Entity Address, Address Line One	2415 Cascade Pointe Boulevard
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28208
City Area Code	980
Local Phone Number	221-3235
Title of 12(b) Security	Common Stock, par value $0.10 per share
Trading Symbol	SEE
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		151,989,913
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001012100
Current Fiscal Year End Date	--12-31