v2.4.1.9

Subsequent Event - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 07, 2015
Subsequent Event [Line Items]
Proceeds from sale of subsidiary	$ 48,324us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates	$ 0us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates	$ 0us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates
Gain on divestiture	27,490us-gaap_GainOrLossOnSaleOfStockInSubsidiary	0us-gaap_GainOrLossOnSaleOfStockInSubsidiary	0us-gaap_GainOrLossOnSaleOfStockInSubsidiary
Rapid Paycard | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of subsidiary				20,000us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates / us-gaap_BusinessAcquisitionAxis = wex_RapidPaycardMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Gain on divestiture				$ 4,000us-gaap_GainOrLossOnSaleOfStockInSubsidiary / us-gaap_BusinessAcquisitionAxis = wex_RapidPaycardMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

X

- Definition

Amount of gain (loss) on sale or disposal of equity in securities of subsidiaries.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph ((13)(g))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Subparagraph g

-Article 9

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

X

- Definition

The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or sale of an entity that is related to it but not strictly controlled.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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X

- Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

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Namespace Prefix:
Data Type:	na
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