v2.4.1.9

Weighted Average Common Shares Outstanding Used to Calculate Earnings Per Share (Detail) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Weighted average common shares outstanding – Basic	38,890us-gaap_WeightedAverageNumberOfSharesOutstandingBasic	38,946us-gaap_WeightedAverageNumberOfSharesOutstandingBasic	38,840us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Unvested restricted stock units	89wex_IncrementalCommonSharesAttributableToUnvestedRestrictedStockUnits	117wex_IncrementalCommonSharesAttributableToUnvestedRestrictedStockUnits	138wex_IncrementalCommonSharesAttributableToUnvestedRestrictedStockUnits
Stock options	21wex_IncrementalCommonSharesAttributableToStockOptions	40wex_IncrementalCommonSharesAttributableToStockOptions	114wex_IncrementalCommonSharesAttributableToStockOptions
Weighted average common shares outstanding – Diluted	39,000us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding	39,103us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding	39,092us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1505-109256

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- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1448-109256



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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Weighted-Average Number of Common Shares Outstanding

-URI http://asc.fasb.org/extlink&oid=6528421

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- Definition

Incremental common shares attributable to stock options.

+ References

No definition available.

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- Definition

Incremental common shares attributable to unvested restricted stock units.

+ References

No definition available.

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