Stockholders' Equity - Summarizes the Company's Pre-tax Share-based Incentive Compensation Expense and Income Tax Benefit (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	$ 48.5	$ 62.9	$ 61.2
Associated tax benefits recognized	11.8	19.7	18.6
2017 Three-year PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	9.8	0.0	0.0
2017 COO and Chief Executive Officer-Designate 2017 New Hire Equity Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.1	0.0	0.0
2016 Three-year PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	2.0	6.3	0.0
2016 President and CEO Inducement Award
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.5	0.5	0.0
2015 Three-year PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	(0.8)	3.5	4.7
2014 Special PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	3.2	8.8	15.7
Share-based compensation expense settled in cash	1.0
2014 Three-year PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.0	4.9	7.0
2013 Three-year PSU Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.0	0.0	4.7
2012 President and COO Four-year Incentive Compensation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.0	0.2	0.3
SLO Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	1.1	2.5	3.7
Other long-term share-based incentive compensation programs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	$ 32.6	$ 36.2	$ 25.1

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash paid related to share-based compensation liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandSeventeenThreeYearPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandSeventeenCOOandCEODesignate2017NewHireEquityAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandSixteenThreeYearPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandSixteenPresidentAndCeoInducementAwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandFifteenThreeYearPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandFourteenSpecialPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandFourteenThreeYearPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandThirteenThreeYearPerformanceShareUnitsAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_TwoThousandTwelvePresidentAndCooFourYearIncentiveCompensationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_StockLeverageOpportunityAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=see_OtherLongTermShareBasedIncentiveCompensationProgramsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: