Revenue Recognition - Summary of Revenue Recognition (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue Recognition [Abstract]
Gain (loss) on change in fair value of other real estate owned and other assets not within scope of ASC 606	$ 3.7	$ (0.1)	$ 3.8	$ (0.1)

Gain (loss) on change in fair value of other real estate owned and other assets not within scope of ASC 606.

No definition available.

Name:	wsbc_GainLossOnChangeInFairValueOfOtherRealEstateOwnedAndOtherAssetsNotWithinScopeOfASC606
Namespace Prefix:	wsbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration