XML 12 R1.htm IDEA: XBRL DOCUMENT v3.20.2
COVER PAGE - shares
 9 Months Ended
Sep. 30, 2020
Nov. 06, 2020
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2020  
Document Transition Report false  
Entity File Number 001-14989  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 25-1723342  
Entity Address, Address Line One 225 West Station Square DriveSuite 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 454-2200  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   50,042,827
Entity Registrant Name WESCO International, Inc.  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Entity Central Index Key 0000929008  
Entity Listings [Line Items]    
Security Exchange Name NYSE  
Document Period End Date Sep. 30, 2020  
Series A Preferred Stock [Member]    
Cover [Abstract]    
Title of 12(b) Security Depositary Shares, each representing a 1/1,00th interest in a share of Series A Fixed-Rate Reset Cumulative Perpetual Preferred Stock  
Trading Symbol WCC PR A  
Security Exchange Name NYSE  
Entity Listings [Line Items]    
Title of 12(b) Security Depositary Shares, each representing a 1/1,00th interest in a share of Series A Fixed-Rate Reset Cumulative Perpetual Preferred Stock  
Trading Symbol WCC PR A  
Security Exchange Name NYSE  
Preferred Share Purchase Right [Member]    
Cover [Abstract]    
Title of 12(b) Security Preferred Share Purchase Rights  
Trading Symbol N/A  
Security Exchange Name NYSE  
Entity Listings [Line Items]    
Title of 12(b) Security Preferred Share Purchase Rights  
Trading Symbol N/A  
Security Exchange Name NYSE  
Common Class A [Member]    
Cover [Abstract]    
Title of 12(b) Security Common Stock, par value $.01 per share  
Trading Symbol WCC  
Entity Listings [Line Items]    
Title of 12(b) Security Common Stock, par value $.01 per share  
Trading Symbol WCC