Revenue Recognition, Contracts with Customers - Narrative (Details) $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($)
Revenue From Contract With Customer [Abstract]
Revenue recognized from performance obligations satisfied In previous periods	$ 2.0
Revenue recognized that was included in contract liability	$ 0.7

Contract with Customer, Performance Obligation Satisfied in Previous Period

No definition available.

Name:	see_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod
Namespace Prefix:	see_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration