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

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

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

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

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.

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

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

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569655-111683

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 24

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4616395-111683

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

The number of countries in which the entity operates as of balance sheet date.

No definition available.

Name:	us-gaap_NumberOfCountriesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Name:	us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

No definition available.

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

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Income Tax Liabilities

No definition available.

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

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

No definition available.

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

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Licensing Agreements Intangible Asset

No definition available.

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

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Tangible Assets and Liabilities

No definition available.

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

Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Tangible Assets and Liabilities

No definition available.

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

Business Combination Provisional Information Initial Accounting Incomplete Adjustment to Statements of Operations and Cash Flows

No definition available.

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

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

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

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