Pro Forma Results of Operations of Evolution1 (Details) (Evolution1, USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Evolution1
Business Acquisition [Line Items]
Revenue	$ 225,181	$ 207,905	$ 653,192	$ 589,123
Net income attributable to WEX Inc.	$ 69,889	$ 37,309	$ 141,206	$ 98,303
Pro forma net income attributable to WEX Inc. per common share:
Net income per share – basic (in usd per share)	$ 1.80	$ 0.96	$ 3.63	$ 2.52
Net income per share – diluted (in usd per share)	$ 1.79	$ 0.95	$ 3.62	$ 2.51

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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+ References

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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