Fair Value Measurement - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Fair value transfer amount	$ 0wsbc_FairValueTransfersBetweenLevel	$ 0wsbc_FairValueTransfersBetweenLevel

The amount of the transfers between levels of the fair value hierarchy.

No definition available.

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