v2.4.1.9

Financing Debt - Additional Information - 2013 Credit Agreement (Details) (USD $)	0 Months Ended
	Jan. 18, 2013	Dec. 31, 2014	Dec. 31, 2013	Jan. 17, 2013	May 23, 2011
Debt Instrument [Line Items]
Credit agreement loan, maximum		$ 125,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity	$ 125,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
2013 Credit Agreement
Debt Instrument [Line Items]
Credit agreement loan, term	5 years
Increase in credit agreement loan	100,000,000us-gaap_ProceedsFromLinesOfCredit / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Term Loans Facility | 2013 Credit Agreement
Debt Instrument [Line Items]
Credit agreement loan, maximum	300,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = wex_CreditFacilityTermLoansMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember			185,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = wex_CreditFacilityTermLoansMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Revolving Credit Facility | 2013 Credit Agreement
Debt Instrument [Line Items]
Credit agreement loan, term	5 years
Credit agreement loan, maximum	800,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember			700,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Senior Subordinated Notes | 2013 Credit Agreement
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount	300,000,000us-gaap_DebtInstrumentFaceAmount / us-gaap_CreditFacilityAxis = us-gaap_SeniorSubordinatedNotesMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember
Letter of Credit | Revolving Credit Facility | 2013 Credit Agreement
Debt Instrument [Line Items]
Credit agreement loan, maximum					$ 150,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = wex_TwoThousandAndThirteenCreditAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_LetterOfCreditMember

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

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

X

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682



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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690



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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Line of credit facility. term of credit

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SeniorSubordinatedNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CreditFacilityAxis=wex_CreditFacilityTermLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=wex_TwoThousandAndThirteenCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: