v2.4.1.9

Cash And Dividend Restrictions - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Reserve balance on deposits	$ 31,127,000us-gaap_CashReserveDepositRequiredAndMade	$ 28,384,000us-gaap_CashReserveDepositRequiredAndMade
Leverage ratio (higher than)	1.75wex_MaximumLeverageRatioForPaymentOfDividendsAndStockRepurchases
Maximum restricted payments, including dividends, per annum	25,000,000wex_RestrictedPaymentsUnderRevolvingCreditAgreementOnDividends
Percentage of transfer to surplus fund	10.00%wex_MinimumRequiredPercentageOfEachOfEntitysVariableInterestEntitysAfterTaxProfitsToAllocateToStatutorySurplusFund
Required percentage of surplus to capital stock	100.00%wex_RequiredPercentageOfStatutorySurplusReserveFundToRegisteredCapital
Capital stock	$ 5,250,000us-gaap_DividendPaymentsRestrictionsScheduleStatutoryCapitalAndSurplus1
Capital surplus as percent of capital stock	100.00%wex_StatutorySurplusReserveFundPercentage

X

- Definition

Cash deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 305

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6478312&loc=d3e61473-112792

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

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

X

- Definition

Amount of statutory capital and surplus computed using prescribed or permitted statutory accounting practice.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529

+ Details

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

X

- Definition

Maximum Leverage Ratio For Payment Of Dividends And Stock Repurchases

+ References

No definition available.

+ Details

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

X

- Definition

Minimum Required Percentage Of Each Of Entitys VIEs After Tax Profits To Allocate To Statutory Surplus Fund

+ References

No definition available.

+ Details

Name:	wex_MinimumRequiredPercentageOfEachOfEntitysVariableInterestEntitysAfterTaxProfitsToAllocateToStatutorySurplusFund
Namespace Prefix:	wex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Required Percentage Of Statutory Surplus Reserve Fund To Registered Capital

+ References

No definition available.

+ Details

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Namespace Prefix:	wex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Restricted payments under revolving credit agreement on dividends.

+ References

No definition available.

+ Details

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Namespace Prefix:	wex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Statutory Surplus Reserve Fund Percentage

+ References

No definition available.

+ Details

Name:	wex_StatutorySurplusReserveFundPercentage
Namespace Prefix:	wex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration