v3.3.0.814

Derivative Instruments Derivative Instruments - Fuel Derivate Program (Details) - Price Risk Derivative [Member]	Sep. 30, 2015
Fourth Quarter 2015 [Member]
Derivative [Line Items]
Fuel price sensitive derivative instrument heading percentage	0.40
First Quarter 2016 [Member]
Derivative [Line Items]
Fuel price sensitive derivative instrument heading percentage	0.20
After First Quarter 2016 [Member]
Derivative [Line Items]
Fuel price sensitive derivative instrument heading percentage	0

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

X

- Definition

Percentage Hedged by Fuel Price Derivatives

+ References

No definition available.

+ Details

Name:	wex_PercentageHedgedbyFuelPriceDerivatives
Namespace Prefix:	wex_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_PriceRiskDerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=wex_FourthQuarter2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=wex_FirstQuarter2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=wex_AfterFirstQuarter2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: