Revenue Recognition, Contracts with Customers - Revenue Remaining Performance Obligations (Details) $ in Millions	Mar. 31, 2018 USD ($)
Revenue Performance Obligation [Abstract]
Revenue, remaining performance obligation, Short-term	$ 2.8
Revenue, remaining performance obligation, Long-term	3.5
Total revenue, expected to be recognized	$ 6.3

Revenue, Remaining Performance Obligation, Noncurrent

No definition available.

Name:	see_RevenueRemainingPerformanceObligationNoncurrent
Namespace Prefix:	see_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant