v2.4.1.9

Noncontrolling Interest - Additional Information (Detail)	0 Months Ended
	Aug. 30, 2012	Dec. 31, 2014	Dec. 31, 2013
Unik Financial Services
Redeemable Noncontrolling Interest [Line Items]
Percent of ownership interest acquired	51.00%us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired / us-gaap_BusinessAcquisitionAxis = wex_UnikSAMember	51.00%us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired / us-gaap_BusinessAcquisitionAxis = wex_UnikSAMember
Period to acquire remaining shares	3 years
WEX Europe Services
Redeemable Noncontrolling Interest [Line Items]
Percent of ownership interest acquired			75.00%us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired / us-gaap_BusinessAcquisitionAxis = wex_WEXEuropeServicesMember

X

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ 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 (c)

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

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

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

X

- Definition

Purchase Agreement Period

+ References

No definition available.

+ Details

Name:	wex_PurchaseAgreementPeriod
Namespace Prefix:	wex_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=wex_UnikSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=wex_WEXEuropeServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: