v2.4.1.9

Business Acquisitions and Other Intangible Assets Acquisitions - Additional Information - Acquisition of CorporatePay (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	May 11, 2012
Business Acquisition [Line Items]
Valuation allowance		$ 2,210us-gaap_DeferredTaxAssetsValuationAllowance	$ 1,292us-gaap_DeferredTaxAssetsValuationAllowance
CorporatePay
Business Acquisition [Line Items]
Consideration paid (net of cash acquired)				27,800us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Increase in accounts receivable	508wex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccountsReceivable / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Decrease in deferred taxes	32wex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Increase in intangible assets	140us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Decrease in goodwill	(247)wex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentGoodwill / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Increase in accrued expenses	369wex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccruedExpenses / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember
Valuation allowance				$ 1,219us-gaap_DeferredTaxAssetsValuationAllowance / us-gaap_BusinessAcquisitionAxis = wex_CorporatepayMember

X

- Details

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

X

- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to intangibles acquired in connection with a business combination for which the initial accounting was incomplete.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1500-128463

+ Details

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

X

- Definition

Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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

X

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

+ Details

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

X

- Definition

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Receivable

+ References

No definition available.

+ Details

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

X

- Definition

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accrued Expenses

+ References

No definition available.

+ Details

Name:	wex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccruedExpenses
Namespace Prefix:	wex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Assets

+ References

No definition available.

+ Details

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

X

- Definition

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill

+ References

No definition available.

+ Details

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

X

- Details

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