Cover
Oct. 14, 2020
Cover [Abstract]  
Document Type 8-K
Document Period End Date Oct. 12, 2020
Entity Registrant Name WEX INC.
Entity Central Index Key 0001309108
Amendment Flag false
Entity Incorporation, State or Country Code DE
Entity File Number 001-32426
Entity Tax Identification Number 01-0526993
Entity Address, Address Line One 1 Hancock Street
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
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock, $0.01 par value
Trading Symbol WEX
Security Exchange Name NYSE
Entity Emerging Growth Company false