v2.4.1.9
Accumulated Other Comprehensive (Loss) Income (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]    
Ending balance $ (50,581)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax $ (15,495)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Unrealized Gains and Losses on Available-for-Sale Securities    
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]    
Beginning balance (433)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
197us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Other comprehensive (loss) income 304us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
(630)us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Ending balance (129)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
(433)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Accumulated Other Comprehensive Income (Loss), Tax 1,453wex_AccumulatedOtherComprehensiveIncomeLossTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
173wex_AccumulatedOtherComprehensiveIncomeLossTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Foreign Currency Items    
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]    
Beginning balance (15,062)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember
37,182us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember
Other comprehensive (loss) income (35,390)us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember
(52,244)us-gaap_OtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember
Ending balance $ (50,452)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember
$ (15,062)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedTranslationAdjustmentMember