XML 19 R1.htm IDEA: XBRL DOCUMENT v3.22.0.1
Cover - USD ($)
 12 Months Ended
Dec. 31, 2021
Feb. 16, 2022
Jun. 30, 2021
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2021    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-32426    
Entity Registrant Name WEX INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 01-0526993    
Entity Address, Address Line One 1 Hancock St.,    
Entity Address, City or Town Portland,    
Entity Address, State or Province ME    
Entity Address, Postal Zip Code 04101    
City Area Code 207    
Local Phone Number 773-8171    
Title of 12(b) Security Common Stock, $0.01 par value    
Trading Symbol WEX    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
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    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 8,642,402,604
Entity Common Stock, Shares Outstanding   44,830,224  
Documents Incorporated by Reference Portions of the Company’s definitive Proxy Statement to be delivered to stockholders in connection with the Company's 2022 Annual Meeting of Stockholders (the “2022 Proxy Statement”) are incorporated by reference into Part III of this 10–K. With the exception of the sections of the 2022 Proxy Statement specifically incorporated herein by reference, the 2022 Proxy Statement is not deemed to be filed as part of this Annual Report on 10–K.    
Entity Central Index Key 0001309108    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus (Q1,Q2,Q3,FY) FY    
Amendment Flag false