Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

- Definition

Debt Covenant, Ratio of EBIT to Interest Charges

+ References

No definition available.

+ Details

Name:	wex_DebtCovenantRatioofEBITtoInterestCharges
Namespace Prefix:	wex_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Permissible ratio of EBIT to interest charges Company may elect up to for four fiscal quarters in connection with certain acquisitions.

+ References

No definition available.

+ Details

Name:	wex_DebtCovenantRatioofEBITtoInterestCharges1
Namespace Prefix:	wex_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Covenant, Ratio of Funded Indebtedness to EBITDA

+ References

No definition available.

+ Details

Name:	wex_DebtCovenantRatioofFundedIndebtednesstoEBITDA
Namespace Prefix:	wex_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Permissible ratio of funded indebtedness to EBITDA Company may elect up to for two fiscal quarters in connection with certain acquisitions.

+ References

No definition available.

+ Details

Name:	wex_DebtCovenantRatioofFundedIndebtednesstoEBITDA1
Namespace Prefix:	wex_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=wex_TwoThousandAndFourteenCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wex_TwoThousandAndThirteenCreditAgreementMember
Namespace Prefix:
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Period Type:

Financing Debt - Additional Information - 2014 Credit Agreement (Details) (USD $)	0 Months Ended
	Aug. 22, 2014	Dec. 31, 2014	Dec. 31, 2013	Aug. 21, 2014
Debt Instrument [Line Items]
Credit agreement loan, maximum		$ 125,000,000	$ 125,000,000
2014 Credit Agreement
Debt Instrument [Line Items]
Credit agreement loan, maximum	222,500,000
2014 Credit Agreement \| Senior Notes
Debt Instrument [Line Items]
Weighted average interest rate		3.10%
2014 Credit Agreement \| Minimum
Debt Instrument [Line Items]
Ratio of EBIT to interest charges (no less than)	3.00
Ratio of EBIT to interest charges	3.75
2014 Credit Agreement \| Maximum
Debt Instrument [Line Items]
Ratio of funded indebtedness to EBITDA (no more than)	3.25
Ratio of funded indebtedness to EBITDA	4.25
2014 Credit Agreement \| Interest Rate Option Two \| Eurocurrency Rate
Debt Instrument [Line Items]
Credit facility, rate	1.00%
2014 Credit Agreement \| Term Loans Facility
Debt Instrument [Line Items]
Credit agreement loan, maximum	500,000,000
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option One \| Minimum \| Eurocurrency Rate
Debt Instrument [Line Items]
Credit facility, rate	1.25%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option One \| Maximum \| Eurocurrency Rate
Debt Instrument [Line Items]
Credit facility, rate	2.75%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option Two \| Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Credit facility, rate	0.50%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option Two \| Minimum
Debt Instrument [Line Items]
Commitment fee percentage	0.20%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option Two \| Minimum \| Eurocurrency Rate
Debt Instrument [Line Items]
Credit facility, rate	0.25%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option Two \| Maximum
Debt Instrument [Line Items]
Commitment fee percentage	0.45%
2014 Credit Agreement \| Term Loans Facility \| Interest Rate Option Two \| Maximum \| Eurocurrency Rate
Debt Instrument [Line Items]
Credit facility, rate	1.75%
2014 Credit Agreement \| Revolving Credit Facility
Debt Instrument [Line Items]
Credit agreement loan, maximum	700,000,000
2014 Credit Agreement \| Letter of Credit
Debt Instrument [Line Items]
Credit agreement loan, maximum	150,000,000
2014 Credit Agreement \| Swingline Loans
Debt Instrument [Line Items]
Credit agreement loan, maximum	20,000,000
2013 Credit Agreement \| Term Loans Facility
Debt Instrument [Line Items]
Credit agreement loan, maximum				$ 277,500,000