Business Acquisitions - Pro Forma Results of Operations of Evolution1 (Details) - Evolution1 [Member] - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 9 Months Ended |
|---|---|---|
Sep. 30, 2014 |
Sep. 30, 2014 |
|
| Business Acquisition [Line Items] | ||
| Revenue | $ 225,181 | $ 653,192 |
| Net income attributable to WEX Inc. | $ 69,889 | $ 141,206 |
| Pro forma net income attributable to WEX Inc. per common share: | ||
| Net income per share – basic (in usd per share) | $ 1.80 | $ 3.63 |
| Net income per share – diluted (in usd per share) | $ 1.79 | $ 3.62 |