XML 61 R51.htm IDEA: XBRL DOCUMENT
v3.19.2

Loans and the Allowance for Credit Losses - Allowance for Credit Losses and Recorded Investments in Loans (Parenthetical) (Detail) - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 | Dec. 31, 2018
Receivables [Abstract] |  |
Troubled debt restructuring threshold | $ 1 | $ 1

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Threshold for individually evaluating commercial loans for impairment. + References No definition available. + Details
Name: | wsbc_ThresholdForIndividuallyEvaluatingCommercialLoansForImpairment
Namespace Prefix: | wsbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration