v2.4.1.9

Segment Information - Reportable Segment Results (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 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
Segment Reporting Disclosure [Line Items]
Total 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
Operating interest expense									6,437us-gaap_InterestExpenseDebt	4,287us-gaap_InterestExpenseDebt	4,990us-gaap_InterestExpenseDebt
Depreciation and Amortization									73,022us-gaap_DepreciationDepletionAndAmortization	60,563us-gaap_DepreciationDepletionAndAmortization	50,267us-gaap_DepreciationDepletionAndAmortization
Adjusted Pre-Tax Income before NCI									289,259wex_AdjustedNetIncome	286,983wex_AdjustedNetIncome	262,788wex_AdjustedNetIncome
Fleet Payment Solutions Segment
Segment Reporting Disclosure [Line Items]
Total Revenues									562,169us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	527,424us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	470,591us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember
Operating interest expense									2,778us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	1,802us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	3,377us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember
Depreciation and Amortization									26,046us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	23,351us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	23,721us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember
Adjusted Pre-Tax Income before NCI									200,081wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	218,187wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember	214,657wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_FleetPaymentSolutionsMember
Other Payment Solutions Segment
Segment Reporting Disclosure [Line Items]
Total Revenues									255,478us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	190,039us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	152,560us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember
Operating interest expense									3,659us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	2,485us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	1,613us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember
Depreciation and Amortization									3,712us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	1,710us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	1,663us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember
Adjusted Pre-Tax Income before NCI									89,178wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	68,796wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember	48,131wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_OtherPaymentSolutionsMember
Total
Segment Reporting Disclosure [Line Items]
Total Revenues									817,647us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	717,463us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	623,151us-gaap_SalesRevenueNet / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember
Operating interest expense									6,437us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	4,287us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	4,990us-gaap_InterestExpenseDebt / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember
Depreciation and Amortization									29,758us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	25,061us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	25,384us-gaap_DepreciationDepletionAndAmortization / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember
Adjusted Pre-Tax Income before NCI									$ 289,259wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	$ 286,983wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember	$ 262,788wex_AdjustedNetIncome / us-gaap_StatementBusinessSegmentsAxis = wex_SegmentReportingTotalMember

X

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

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No definition available.

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