Related Parties - Related Party Transactions in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Related Party [Abstract]
Leasing revenue from related parties	$ (292)	$ 0
Management fees and recharge income on transactions with affiliates	0	(1,351)
Interest income on notes due from affiliates	0	(2,584)
Interest expense on notes due to affiliates	0	14,737
Total related party expenses, net	$ (292)	$ 10,802

Amount of interest expense incurred on a debt or other obligation to related party.

No definition available.

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

Amount of interest income earned from interest-bearing assets owed to the entity by related party.

No definition available.

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

Related Party [Abstract]

No definition available.

Related Party Transaction, Income (Expenses) from Transactions with Related Party, Net

No definition available.

Name:	wsc_RelatedPartyTransactionIncomeExpensesfromTransactionswithRelatedPartyNet
Namespace Prefix:	wsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Related Party Transaction, Management Fees and Recharge Income (Expenses) from Transactions with Related Party

No definition available.

Name:	wsc_RelatedPartyTransactionManagementFeesandRechargeIncomeExpensesfromTransactionswithRelatedParty
Namespace Prefix:	wsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Related Party Transaction, Operating Leases, Income Statement, Lease Revenue

No definition available.

Name:	wsc_RelatedPartyTransactionOperatingLeasesIncomeStatementLeaseRevenue
Namespace Prefix:	wsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration