v2.4.1.9
Business Acquisitions and Other Intangible Assets Acquisitions - Additional Information - Acquisition of Evolution1 (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended 0 Months Ended 6 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jul. 16, 2014
Dec. 31, 2014
Business Acquisition [Line Items]                          
Net revenues $ 211,864us-gaap_SalesRevenueNet $ 222,134us-gaap_SalesRevenueNet $ 201,581us-gaap_SalesRevenueNet $ 182,068us-gaap_SalesRevenueNet $ 182,283us-gaap_SalesRevenueNet $ 191,525us-gaap_SalesRevenueNet $ 178,285us-gaap_SalesRevenueNet $ 165,370us-gaap_SalesRevenueNet $ 817,647us-gaap_SalesRevenueNet $ 717,463us-gaap_SalesRevenueNet $ 623,151us-gaap_SalesRevenueNet    
Net earnings attributable to WEX Inc. (47,893)us-gaap_NetIncomeLoss (74,443)us-gaap_NetIncomeLoss (43,333)us-gaap_NetIncomeLoss (36,542)us-gaap_NetIncomeLoss (34,468)us-gaap_NetIncomeLoss (43,838)us-gaap_NetIncomeLoss (42,213)us-gaap_NetIncomeLoss (28,689)us-gaap_NetIncomeLoss (202,211)us-gaap_NetIncomeLoss (149,208)us-gaap_NetIncomeLoss (96,922)us-gaap_NetIncomeLoss    
Evolution1                          
Business Acquisition [Line Items]                          
Payments to acquire business                       532,174us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= wex_EvolutionOneMember		  
Net revenues                         35,976us-gaap_SalesRevenueNet
/ us-gaap_BusinessAcquisitionAxis
= wex_EvolutionOneMember
Net earnings attributable to WEX Inc.                         $ 512us-gaap_NetIncomeLoss
/ us-gaap_BusinessAcquisitionAxis
= wex_EvolutionOneMember