| Document and Entity Information | Aug. 06, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | WESBANCO INC |
| Amendment Flag | false |
| Entity Central Index Key | 0000203596 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Aug. 6, 2020 |
| Entity Incorporation State Country Code | WV |
| Entity File Number | 000-08467 |
| Entity Tax Identification Number | 55-0571723 |
| Entity Address, Address Line One | 1 Bank Plaza |
| Entity Address, City or Town | Wheeling |
| Entity Address, State or Province | WV |
| Entity Address, Postal Zip Code | 26003 |
| City Area Code | (304) |
| Local Phone Number | 234-9000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock $2.0833 Par Value |
| Trading Symbol | WSBC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
