v2.4.1.9

Financing Debt - Additional Information - $400 Million Notes Outstanding (Details) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended
	Jan. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 18, 2013	Jan. 17, 2013
Debt Instrument [Line Items]
Notes outstanding			$ 400,000,000us-gaap_SeniorNotes	$ 400,000,000us-gaap_SeniorNotes
Redemption price as percentage of principal amount	104.75%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount
Percentage of notes Company may redeem	35.00%wex_DebtInstrumentRedemptionPercentageOfPrincipalValue
Percentage of principal amount Company must offer to repurchase	101.00%wex_DebtInstrumentRepurchasePricePercentageOnPrincipalAmountPlusAccruedAndUnpaidInterest
Credit agreement loan, maximum			125,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity	125,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Deferred finance costs, net				15,547,000us-gaap_DeferredFinanceCostsNet
Previous issuance costs, wrote-off		1,000,000us-gaap_WriteOffOfDeferredDebtIssuanceCost	0us-gaap_WriteOffOfDeferredDebtIssuanceCost	1,004,000us-gaap_WriteOffOfDeferredDebtIssuanceCost	0us-gaap_WriteOffOfDeferredDebtIssuanceCost
Senior Notes Redeemed During 12 Months Beginning February 1, 2018 [Member]
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	102.375%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount / us-gaap_LineOfCreditFacilityAxis = wex_SeniorNotesRedeemedDuringTwelveMonthsBeginningFebruaryOneTwentyEighteenMember
Senior Notes Redeemed During 12 Months Beginning February 1, 2019 [Member]
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	101.583%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount / us-gaap_LineOfCreditFacilityAxis = wex_SeniorNotesRedeemedDuringTwelveMonthsBeginningFebruaryOneTwentyNineteenMember
Senior Notes Redeemed During 12 Months Beginning February 1, 2020 [Member]
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	100.792%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount / us-gaap_LineOfCreditFacilityAxis = wex_SeniorNotesRedeemedDuringTwelveMonthsBeginningFebruaryOneTwentyTwentyMember
Senior Notes Redeemed During 12 Months Beginning February 1, 2021 [Member]
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	100.00%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount / us-gaap_LineOfCreditFacilityAxis = wex_SeniorNotesRedeemedDuringTwelveMonthsBeginningFebruaryOneTwentyTwentyOneMember
Senior Notes Redeemed Prior To February 1, 2018 [Member]
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	100.00%wex_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount / us-gaap_LineOfCreditFacilityAxis = wex_SeniorNotesRedeemedPriorToFebruaryOneTwentyEighteenMember
2013 Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Credit agreement loan, maximum						800,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember	700,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Senior Notes
Debt Instrument [Line Items]
Notes outstanding	400,000,000us-gaap_SeniorNotes / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember
Debt instrument, stated rate	4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember		4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember
Issuance price as percent of principal amount	100.00%wex_DebtInstrumentIssuancePricePercentOfTotal / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember
Senior Notes | 2013 Credit Agreement
Debt Instrument [Line Items]
Notes outstanding			400,000,000us-gaap_SeniorNotes / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember	400,000,000us-gaap_SeniorNotes / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Senior Notes | 2013 Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Credit agreement loan, maximum						$ 700,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_DebtInstrumentAxis = us-gaap_SeniorNotesMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember

X

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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