| Document and Entity Information | Feb. 26, 2024 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | WESCO INTERNATIONAL INC |
| Amendment Flag | false |
| Entity Central Index Key | 0000929008 |
| Document Type | 8-K |
| Document Period End Date | Feb. 26, 2024 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-14989 |
| Entity Tax Identification Number | 25-1723342 |
| Entity Address, Address Line One | 225 West Station Square Drive |
| Entity Address, Address Line Two | Suite 700 |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15219 |
| City Area Code | (412) |
| Local Phone Number | 454-220 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock, par value $0.01 per share |
| Trading Symbol | WCC |
| Security Exchange Name | NYSE |
| Series A Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Depositary Shares, each representing a 1/1,000th interest in a share of Series A Fixed-Rate Reset Cumulative Perpetual Preferred Stock |
| Trading Symbol | WCC PR A |
| Security Exchange Name | NYSE |
