Comprehensive Income/(Loss) - Components of Accumulated Other Comprehensive Income (Detail) (Parenthetical) (Detail)	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Percentage of Federal and State income tax rate	23.00%	23.00%

Income tax expense benefit combined federal and state income tax rate.

No definition available.

Name:	wsbc_IncomeTaxExpenseBenefitCombinedFederalAndStateIncomeTaxRate
Namespace Prefix:	wsbc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration