Loans and the Allowance for Credit Losses - Recorded Investment in Non-Accrual Loans and TDRs (Parenthetical) (Detail)	Dec. 31, 2016 USD ($) Borrowers
Receivables [Abstract]
Number of borrowers with loans greater than one million \| Borrowers	2
Borrowers with large amount of loans outstanding, minimum amount of loans per borrower	$ 1,000,000
Borrowers with large amount of loans outstanding, net	$ 4,300,000

Number of borrowers with nonaccrual Loan advances outstanding greater than one million U.S. dollars.

No definition available.

Name:	wsbc_NonaccrualLoansOutstandingGreaterThanOneMillionDollarsPerBorrowerNumberOfBorrowers
Namespace Prefix:	wsbc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant