v2.4.1.9
Property, Equipment And Capitalized Software, Net (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross $ 274,978us-gaap_PropertyPlantAndEquipmentGross $ 217,675us-gaap_PropertyPlantAndEquipmentGross  
Less accumulated depreciation and amortization (169,382)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment (145,400)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment  
Total property, equipment and capitalized software, net 105,596us-gaap_PropertyPlantAndEquipmentNet 72,275us-gaap_PropertyPlantAndEquipmentNet 60,097us-gaap_PropertyPlantAndEquipmentNet
Furniture, fixtures and equipment      
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross 56,177us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= wex_FurnitureFixturesAndEquipmentMember
44,109us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= wex_FurnitureFixturesAndEquipmentMember
 
Computer Software      
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross 184,868us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_ComputerSoftwareIntangibleAssetMember
160,796us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_ComputerSoftwareIntangibleAssetMember
 
Software under development      
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross 21,937us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_SoftwareDevelopmentMember
7,675us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_SoftwareDevelopmentMember
 
Leasehold Improvements      
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross 11,239us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
5,095us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
 
Capital leases      
Property, Plant and Equipment [Line Items]      
Property, equipment and capitalized software, gross $ 757us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_AssetsHeldUnderCapitalLeasesMember
$ 0us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_AssetsHeldUnderCapitalLeasesMember