WEX (WEX) 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 24, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'WEX	'
Entity Registrant Name	'WEX INC.	'
Entity Central Index Key	'0001309108	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	38,875,635

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Cash and cash equivalents	$391,171	$197,662
Accounts receivable (less reserve for credit losses of $8,954 in 2013 and $11,709 in 2012)	1,913,614	1,556,275
Available-for-sale securities	16,208	16,350
Fuel price derivatives, at fair value	488	0
Property, equipment and capitalized software (net of accumulated depreciation of $139,684 in 2013 and $125,659 in 2012)	70,097	60,097
Deferred income taxes, net	92,693	121,007
Goodwill	824,307	847,986
Other intangible assets, net	209,074	241,950
Other assets	139,805	90,538
Total assets	3,657,457	3,131,865
Liabilities and Stockholders’ Equity	'	'
Accounts payable	706,927	527,838
Accrued expenses	79,754	67,419
Income taxes payable	14,228	10,038
Deposits	1,158,196	890,345
Borrowed federal funds	0	48,400
Revolving line-of-credit facilities and term loan	288,750	621,000
Deferred income taxes, net	11,464	18,407
Notes outstanding	400,000	0
Amounts due under tax receivable agreement	79,705	86,550
Fuel price derivatives, at fair value	983	1,729
Other liabilities	15,822	20,546
Total liabilities	2,755,829	2,292,272
Commitments and contingencies (Note 14)	'	'
Redeemable noncontrolling interest (Note 11)	19,762	21,662
Stockholders’ Equity	'	'
Common stock $0.01 par value; 175,000 shares authorized; 42,897 in 2013 and 42,586 in 2012 shares issued; 38,982 in 2013 and 38,908 in 2012 shares outstanding	429	426
Additional paid-in capital	166,615	162,470
Retained earnings	845,051	730,311
Accumulated other comprehensive income	337	37,379
Less treasury stock at cost; 4,007 shares in 2013 and 3,766 in 2012	-130,566	-112,655
Total stockholders’ equity	881,866	817,931
Total liabilities and stockholders’ equity	$3,657,457	$3,131,865

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accounts receivable, reserve for credit losses	$8,954	$11,709
Property, equipment and capitalized software, accumulated depreciation	$139,684	$125,659
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	42,897,000	42,586,000
Common stock, shares outstanding	38,982,000	38,908,000
Treasury stock, shares	4,007,000	3,766,000

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	'	'	'	'
Fleet payment solutions	$136,874	$117,877	$393,953	$341,709
Other payment solutions	54,651	43,090	141,227	112,444
Total revenues	191,525	160,967	535,180	454,153
Expenses	'	'	'	'
Salary and other personnel	41,469	28,823	122,193	87,501
Service fees	29,352	28,968	79,765	74,046
Provision for credit losses	5,015	5,647	13,686	14,874
Technology leasing and support	6,799	4,577	18,712	13,718
Occupancy and equipment	3,822	3,032	11,818	9,062
Depreciation, amortization and impairment	14,160	27,877	43,268	50,591
Operating interest expense	976	1,243	3,205	3,430
Cost of hardware and equipment sold	1,055	759	3,266	2,270
Other	10,984	8,764	33,763	26,541
Total operating expenses	113,632	109,690	329,676	282,033
Operating income	77,893	51,277	205,504	172,120
Financing interest expense	-7,369	-2,302	-22,077	-6,877
Gain (loss) on foreign currency transactions	2,968	180	1,708	-312
Net realized and unrealized loss on fuel price derivatives	-3,640	-14,026	-2,781	-12,046
Decrease in tax refund due to former shareholders of RD Card Holdings Australia	0	0	0	9,750
Decrease in amount due under tax receivable agreement	150	0	150	0
Income before income taxes	70,002	35,129	182,504	162,635
Income taxes	26,224	20,845	68,097	94,780
Net income	43,778	14,284	114,407	67,855
Less: Net loss from noncontrolling interest	-60	-14	-333	-14
Net earnings attributable to WEX Inc.	$43,838	$14,298	$114,740	$67,869
Net earnings attributable to WEX Inc. per share:	'	'	'	'
Basic (in dollars per share)	$1.12	$0.37	$2.95	$1.75
Diluted (in dollars per share)	$1.12	$0.37	$2.93	$1.74
Weighted average common shares outstanding:	'	'	'	'
Basic (in shares)	38,978	38,793	38,934	38,832
Diluted (in shares)	39,081	38,995	39,102	39,084

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$43,778	$14,284	$114,407	$67,855
Changes in available-for-sale securities, net of tax effect of $(43) and $(289) in 2013 and $27 and $68 in 2012	-73	44	-492	114
Changes in interest rate swap, net of tax effect of $35 for the nine months ended 2012	0	0	0	60
Foreign currency translation	7,856	9,229	-38,117	7,412
Comprehensive income	51,561	23,557	75,798	75,441
Less: comprehensive income (loss) attributable to noncontrolling interest	112	209	-1,900	209
Comprehensive income attributable to WEX Inc.	$51,449	$23,348	$77,698	$75,232

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Changes in available-for-sale securities, tax effect	($43)	$27	($289)	$68
Changes in interest rate swap, tax effect	$0	$0	$0	$35

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Retained Earnings
In Thousands, unless otherwise specified
Beginning Balance at Dec. 31, 2011	$709,315	$423	$146,282	$30,588	($101,367)	$633,389
Beginning Balance (in shares) at Dec. 31, 2011	'	42,252	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Stock issued to employees exercising stock options (in shares)	'	136	'	'	'	'
Stock issued to employees exercising stock options	1,863	1	1,862	'	'	'
Tax benefit from employees’ stock option and restricted stock units	3,049	'	3,049	'	'	'
Stock issued to employees for vesting of restricted stock units (in shares)	'	100	'	'	'	'
Stock issued to employees for vesting of restricted stock units	1	1	'	'	'	'
Stock-based compensation, net of share repurchases for tax withholdings	5,865	'	5,865	'	'	'
Purchase of shares of treasury stock	-11,288	'	'	'	-11,288	'
Changes in available-for-sale securities, net of tax effect of $68 in 2013 and $(289) in 2012	114	'	'	114	'	'
Changes in interest rate swaps, net of tax effect of $35	60	'	'	60	'	'
Foreign currency translation	7,189	'	'	7,189	'	'
Net income	67,869	'	'	'	'	67,869
Ending Balance at Sep. 30, 2012	784,037	425	157,058	37,951	-112,655	701,258
Ending Balance (in shares) at Sep. 30, 2012	'	42,488	'	'	'	'
Beginning Balance at Dec. 31, 2012	817,931	426	162,470	37,379	-112,655	730,311
Beginning Balance (in shares) at Dec. 31, 2012	'	42,586	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Stock issued to employees exercising stock options (in shares)	'	70	'	'	'	'
Stock issued to employees exercising stock options	1,672	1	1,671	'	'	'
Tax benefit from employees’ stock option and restricted stock units	6,509	'	6,509	'	'	'
Stock issued to employees for vesting of restricted stock units (in shares)	'	241	'	'	'	'
Stock issued to employees for vesting of restricted stock units	'	2	-2	'	'	'
Stock-based compensation, net of share repurchases for tax withholdings	-4,033	'	-4,033	'	'	'
Purchase of shares of treasury stock	-17,911	'	'	'	-17,911	'
Changes in available-for-sale securities, net of tax effect of $68 in 2013 and $(289) in 2012	-492	'	'	-492	'	'
Foreign currency translation	-36,550	'	'	-36,550	'	'
Net income	114,740	'	'	'	'	114,740
Ending Balance at Sep. 30, 2013	$881,866	$429	$166,615	$337	($130,566)	$845,051
Ending Balance (in shares) at Sep. 30, 2013	'	42,897	'	'	'	'

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Statement of Stockholders' Equity [Abstract]	'	'
Changes in available-for-sale securities, tax effect	($289)	$68
Changes in interest rate swaps, tax effect	$0	$35

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities	'	'
Net income	$114,407	$67,855
Adjustments to reconcile net income to net cash provided by (used for) operating activities:	'	'
Fair value change of fuel price derivatives	-1,234	1,841
Stock-based compensation	6,882	8,806
Depreciation, amortization and impairment	45,021	35,604
Goodwill impairment	0	16,171
Deferred taxes	23,207	35,392
Provision for credit losses	13,686	14,874
Loss on disposal of property, equipment and capitalized software	637	0
Changes in operating assets and liabilities, net of effects of acquisition:	'	'
Accounts receivable	-384,715	-306,350
Other assets	-39,289	-55,572
Accounts payable	185,284	163,203
Accrued expenses	13,030	-5,755
Income taxes	5,463	16,904
Other liabilities	-826	-12,034
Amounts due under tax receivable agreement	-6,841	-6,245
Net cash used for operating activities	-25,288	-25,306
Cash flows from investing activities	'	'
Purchases of property, equipment and capitalized software	-30,122	-21,796
Purchases of available-for-sale securities	-1,704	-224
Maturities of available-for-sale securities	1,065	1,228
Acquisitions, net of cash	0	-26,217
Net cash used for investing activities	-30,761	-47,009
Cash flows from financing activities	'	'
Excess tax benefits from equity instrument share-based payment arrangements	6,509	3,049
Repurchase of share-based awards to satisfy tax withholdings	-10,917	-2,941
Proceeds from stock option exercises	1,671	1,862
Net change in deposits	267,859	512,456
Net change in borrowed federal funds	-48,400	-6,900
Other financing debt	-3,003	-19,560
Loan origination fee	-12,023	0
Borrowings on notes outstanding	400,000	0
Net activity on 2011 revolving line-of-credit	-438,500	12,200
Purchase of shares of treasury stock	-17,911	-11,288
Net cash provided by financing activities	251,535	481,378
Effect of exchange rate changes on cash and cash equivalents	-1,977	449
Net change in cash and cash equivalents	193,509	409,512
Cash and cash equivalents, beginning of period	197,662	25,791
Cash and cash equivalents, end of period	391,171	435,303
Supplemental cash flow information	'	'
Interest paid	20,291	9,676
Income taxes paid	33,013	39,455
2011 term loan	'	'
Cash flows from financing activities	'	'
Net activity on term loan	-182,500	-7,500
2013 term loan	'	'
Cash flows from financing activities	'	'
Net activity on term loan	288,750	0
Rapid! Financial Services LLC	'	'
Significant non-cash transactions	'	'
Reduction of rapid! – estimated earn out	0	839
UNIK	'	'
Significant non-cash transactions	'	'
Acquisition of UNIK - estimated earn out	0	991
Increase in UNIK – estimated earn out	$198	$0

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	1	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. They do not include all information and notes required by generally accepted accounting principles (“GAAP”) for complete financial statements. However, except as disclosed herein, there have been no material changes in the information disclosed in the notes to consolidated financial statements included in the Annual Report on Form 10-K of WEX Inc. for the year ended December 31, 2012. These unaudited condensed consolidated financial statements should be read in conjunction with the financial statements that are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012, filed with the Securities and Exchange Commission (“SEC”) on March 1, 2013. When used in these notes, the term “Company” means WEX Inc. and all entities included in the consolidated financial statements. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2013, are not necessarily indicative of the results that may be expected for any future quarter(s) or the year ending December 31, 2013.
	The Company adjusted the balance sheet amounts at December 31, 2012, where appropriate, to account for the measurement period adjustments related to the CorporatePay, UNIK and Fleet One purchase price allocations discussed in Note 3, Business Acquisitions, below.
	The presentation of the Company’s consolidated balance sheet for the period ended December 31, 2012 has been corrected for an immaterial error in the classification of foreign deferred tax liabilities. As of December 31, 2012, the foreign jurisdiction deferred tax liability balance was erroneously netted with the domestic deferred tax asset balance and presented on the Consolidated Balance Sheet as a deferred tax asset. This correction of the error resulted in an increase in deferred tax assets and total assets of $18,407 and a corresponding increase in deferred tax liabilities, total liabilities, and total liabilities and stockholders’ equity of $18,407. The result of this correction did not impact the Company’s consolidated statements of income, comprehensive income, stockholders’ equity and cash flows for any period presented.
	Fair Value of Financial Instruments
	The carrying values of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses, and other liabilities approximate their respective fair values due to the short-term nature of such instruments. The carrying values of certificates of deposit, interest-bearing money market deposits, borrowed federal funds and credit agreement borrowings, approximate their respective fair values as the interest rates on these financial instruments are variable. All other financial instruments are reflected at fair value on the condensed consolidated balance sheet.
	The notes outstanding as of September 30, 2013, have a carrying value of $400,000 and fair value of $360,000. The fair value is based on market rates for the issuance of debt.

New_Accounting_Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2013
Accounting Changes and Error Corrections [Abstract]	'
New Accounting Standards	'
	2	New Accounting Standards
	In July 2013, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2013-11 Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (“ASU 2013-11"). The amendments in ASU 2013-11 require entities to present an unrecognized tax benefit, or a portion of an unrecognized tax benefit, in the financial statements as a reduction to a deferred tax asset for a net operating loss ("NOL") carryforward, a similar tax loss, or a tax credit carryforward except when the following exist: (i) an NOL carryforward, a similar tax loss, or a tax credit carryforward is not available as of the reporting date under the governing tax law to settle taxes that would result from the disallowance of the tax position, and (ii) the entity does not intend to use the deferred tax asset for this purpose (provided the tax law permits a choice). If either of these conditions exists, entities should present an unrecognized tax benefit in the financial statements as a liability and should not net the unrecognized tax benefit with a deferred tax asset. ASU 2013-11 is effective for interim and annual periods beginning after December 15, 2013. The Company does not believe that the adoption of ASU 2013-11 will have a material impact on its results of operations when adopted in 2014.
	In February 2013, the FASB issued Accounting Standards Update No. 2013-02 Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This guidance is intended to provide disclosure on items reclassified out of accumulated other comprehensive income either in the notes or parenthetically on the face of the income statement. The required disclosure is in Note 10, Comprehensive Income.

Business_Acquisitions

Business Acquisitions	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Business Acquisitions	'
	3	Business Acquisitions
	Acquisition of CorporatePay
	On May 11, 2012, the Company acquired all of the stock of CorporatePay, a provider of corporate prepaid solutions to the travel industry in the United Kingdom for approximately GBP17,000 (US$27,783 at the time of the acquisition), net of cash acquired. The Company purchased CorporatePay to expand its Other Payment Solutions segment. During the second quarter of 2012, the Company allocated the purchase price of the acquisition based upon a preliminary estimate of the fair values of the assets acquired and liabilities assumed. During the first quarter of 2013, the Company obtained information to assist in determining the fair values of certain tangible and intangible assets acquired and liabilities assumed as of the CorporatePay acquisition date. Based on such information, the Company retrospectively adjusted the fiscal year 2012 comparative information resulting in an increase in accounts receivable of $508, a decrease in deferred taxes of $32, an increase in intangible assets of $140, a decrease in goodwill of $247, and an increase in accrued expenses of $369. There were no changes to the previously reported consolidated statements of operations or statements of cash flows. The valuations of all assets and liabilities have been finalized.
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Consideration paid (net of cash)	$	27,783
	Less:
	Accounts receivable	1,585
	Accounts payable	(629		)
	Other tangible liabilities, net	(4,040		)
	Acquired software(a)	8,233
	Customer relationships(b)	1,614
	Trademarks and trade name(c)	1,453
	Recorded goodwill	$	19,567
	(a)	Weighted average life – 6.2 years.
	(b)	Weighted average life – 6.3 years.
	(c)	Weighted average life – 5.3 years.
	Acquisition of Ownership Interest in UNIK
	On August 30, 2012, the Company acquired a 51 percent ownership interest in UNIK S.A. (“UNIK”), a privately-held provider of payroll cards in Brazil. The Company purchased its interest in UNIK to expand its Other Payment Solutions segment. UNIK is a provider of payroll cards, private label and processing services in Brazil specializing in the retail, government and transportation sectors.
	The investment was achieved through the purchase of newly issued shares of UNIK for approximately R$44,800 (approximately US$22,800, at the time of the acquisition). The purchase agreement also includes a contingent consideration component based on performance milestones. Although the contingent consideration was not capped, the Company estimated the amount of the liability, at the time of acquisition, to be approximately R$2,000 (approximately US$1,000). On June 30, 2013, the Company revised the estimate based on current performance milestones to be approximately US$511, which was paid on July 1, 2013. The agreement further provides the Company with a call option which allows the Company to acquire the remaining shares at specific times over a three-year period. Additionally, the purchase agreement provides the noncontrolling shareholders with the right to put their interest back to the Company at specific times. The put options are exercisable at specific dates subject to the achievement of performance hurdles. Pricing for both the call and put options are based upon multiples of UNIK’s trailing twelve month EBITDA. Subsequent to the acquisition of UNIK, UNIK paid down approximately US$19,600 of existing financing debt. As of September 30, 2013, UNIK has approximately US$6,764 of financing debt, classified in other liabilities on the Company’s condensed consolidated balance sheets.
	During the third quarter of 2012, the Company allocated the purchase price of the acquisition based upon a preliminary estimate of the fair values of the assets acquired and liabilities assumed. Goodwill associated with the transaction is not expected to be deductible for income tax purposes. In addition, the Company has recognized and measured a redeemable noncontrolling interest. The redeemable noncontrolling interest represents the portion of UNIK’s net assets owned by the noncontrolling shareholders and is presented in the mezzanine section on the Company’s condensed consolidated balance sheets. During the third quarter of 2013, the Company obtained information to assist in determining the fair values of certain tangible and intangible assets acquired and liabilities assumed as of the UNIK acquisition date. Based on such information, the Company retrospectively adjusted the fiscal year 2012 comparative information resulting in an increase in deferred taxes of $2,243, an increase in goodwill of $4,355, and an increase in accrued expenses of $6,598. There were no changes to the previously reported consolidated statements of operations or statements of cash flows. The valuations of all assets and liabilities have been finalized.
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Total UNIK value	$	44,701
	Less: Redeemable noncontrolling interest	21,904
	Total purchase price (includes estimated earn out of $991)	$	22,797
	Less:
	Cash	1,566
	Accounts receivable	11,726
	Accounts payable	(12,640		)
	Other tangible liabilities, net	(36,866		)
	Acquired software(a)	14,193
	Customer relationships(b)	15,171
	Trademarks and trade name(c)	1,272
	Recorded goodwill	$	28,375
	(a)	Weighted average life – 6.2 years.
	(b)	Weighted average life – 5.9 years.
	(c)	Weighted average life – 5.5 years.
	Acquisition of Fleet One
	On October 4, 2012, the Company acquired certain assets of Fleet One, a privately-held provider of value-based business payment processing and information management solutions. The Company purchased Fleet One to expand its fuel card and fleet management information services, as well as to accelerate its presence in the over the road market.
	During the fourth quarter of 2012, the Company allocated the purchase price of the acquisition based upon a preliminary estimate of the fair values of the assets acquired and liabilities assumed. During the third quarter of 2013, the Company obtained information to assist in determining the fair values of certain tangible and intangible assets acquired and liabilities assumed as of the Fleet One acquisition date. Based on such information, the Company retrospectively adjusted the fiscal year 2012 comparative information resulting in an decrease in accounts receivable of $47, an increase in deferred taxes of $261, a decrease in goodwill of $407, a decrease in taxes payable of $113 and a decrease in accrued expenses of $80. There were no changes to the previously reported consolidated statements of operations or statements of cash flows. The valuations of all assets and liabilities have been finalized.
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Consideration paid (net of cash)	$	376,258
	Less:
	Accounts receivable	152,527
	Accounts payable	(151,647		)
	Other tangible liabilities, net	(693		)
	Acquired software(a)	35,000
	Customer relationships(b)	74,000
	Trademarks and trade name(c)	4,000
	Recorded goodwill	$	263,071
	(a)	Weighted average life – 6.7 years.
	(b)	Weighted average life – 5.5 years.
	(c)	Weighted average life – 5.5 years.

Reserves_for_Credit_Losses

Reserves for Credit Losses	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Reserves for Credit Losses	'
	4	Reserves for Credit Losses
	In general, the Company’s trade receivables provide for payment terms of 30 days or less. The Company does not extend revolving credit to its customers with respect to these receivables. The portfolio of receivables consists of a large group of smaller balance homogeneous amounts that are collectively evaluated for impairment.
	The following table presents the Company’s aging of accounts receivable:
		Age Analysis of Past Due Financing Receivables, Gross
		as of September 30, 2013, and September 30, 2012
		Current			30-59 Days			60-89 Days			Greater			Total
		and Less			Past Due			Past Due			Than
		Than 30									90 Days
		Days Past									Past
		Due									Due
	2013
	Accounts receivable, trade	$	1,852,563		$	50,691		$	10,718		$	8,596		$	1,922,568
	Percent of total	96.4		%	2.6		%	0.6		%	0.4		%
	2012
	Accounts receivable, trade	$	1,595,483		$	32,031		$	6,123		$	7,130		$	1,640,767
	Percent of total	97.2		%	2		%	0.4		%	0.4		%
	The following table presents changes in reserves for credit losses related to accounts receivable:
		Nine months ended
		September 30,
		2013			2012
	Balance, beginning of period	$	11,709		$	11,526
	Provision for credit losses	13,686			14,874
	Charge-offs	(21,150		)	(20,397		)
	Recoveries of amounts previously charged-off	5,031			4,065
	Currency translation	(322		)	—
	Balance, end of period	$	8,954		$	10,068

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
	5	Goodwill and Other Intangible Assets
	Goodwill
	The changes in goodwill during the first nine months of 2013 were as follows:
		Fleet Payment Solutions Segment			Other			Total
					Payment
					Solutions
					Segment
	Gross goodwill, January 1, 2013, as adjusted	$	779,654		$	85,840		$	865,494
	Impact of foreign currency translation	(21,123		)	(2,556		)	(23,679		)
	Gross goodwill, September 30, 2013	758,531			83,284			841,815
	Accumulated impairment, September 30, 2013	(1,337		)	(16,171		)	(17,508		)
	Net goodwill, September 30, 2013	$	757,194		$	67,113		$	824,307
	The Company had no impairments to goodwill during the nine months ended September 30, 2013.
	Other Intangible Assets
	The changes in other intangible assets during the first nine months of 2013 were as follows:
		Net			Transfer from indefinite-lived intangible assets to definite-lived intangible assets			Amortization			Impact of			Net Carrying
		Carrying									foreign			Amount,
		Amount,									currency			September 30,
		January 1,									translation			2013
		2013
		(As adjusted)
	Definite-lived intangible assets
	Acquired software	$	71,343		$	—		$	(6,350	)	$	(1,584	)	$	63,409
	Customer relationships	150,290			—			(17,264		)	(5,819		)	127,207
	Patent	2,365			—			(341		)	(176		)	1,848
	Trade names	7,407			2,421			(609		)	(116		)	9,103
	Indefinite-lived intangible assets													—
	Trademarks and trade names	10,545			(2,421		)	—			(617		)	7,507
	Total	$	241,950		$	—		$	(24,564	)	$	(8,312	)	$	209,074
	The Company adjusted the balance sheet amount for goodwill and intangible assets at December 31, 2012, to account for the measurement period adjustments related to the CorporatePay, UNIK and Fleet One purchase price allocations.
	During the third quarter of 2013, the Company determined that the intangible asset recorded for the trade name associated with Wright Express Corporation should be reclassified from an indefinite-lived intangible asset to a definite-lived intangible asset due to the current re-branding efforts of changing from the Wright Express brand to the WEX brand initiated domestically and abroad. The Company determined a 10 year life would be appropriate in conjunction with the re-branding strategy initiated during the third quarter of this year.
	The following table presents the estimated amortization expense related to the definite-lived intangible assets listed above for the remainder of 2013 and for each of the five succeeding fiscal years:
	Estimated Amortization Expense
	Remaining 2013	$	8,188
	2014	$	31,541
	2015	$	28,918
	2016	$	25,360
	2017	$	21,625
	2018	$	18,606
	Other intangible assets consist of the following:
		30-Sep-13									31-Dec-12
		Gross			Accumulated			Net Carrying			Gross			Accumulated			Net Carrying
		Carrying			Amortization			Amount			Carrying			Amortization			Amount
		Amount									Amount
	Definite-lived intangible assets
	Acquired software	$	84,023		$	(20,614	)	$	63,409		$	86,527		$	(15,184	)	$	71,343
	Non-compete agreement	100			(100		)	—			100			(100		)	—
	Customer relationships	192,846			(65,639		)	127,207			202,061			(51,771		)	150,290
	Patent	3,083			(1,235		)	1,848			3,430			(1,065		)	2,365
	Trademarks and trade names	10,137			(1,034		)	9,103			7,827			(420		)	7,407
		$	290,189		$	(88,622	)	201,567			$	299,945		$	(68,540	)	231,405
	Indefinite-lived intangible assets
	Trademarks and trade names							7,507									10,545
	Total							$	209,074								$	241,950

Earnings_per_Share

Earnings per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings per Share	'
	6	Earnings per Share
	The following is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the three and nine months ended September 30, 2013 and 2012:
		Three months ended				Nine months ended
		September 30,				September 30,
		2013		2012		2013		2012
	Net earnings attributable to WEX Inc. available for common stockholders – Basic and Diluted	$	43,838	$	14,298	$	114,740	$	67,869
	Weighted average common shares outstanding – Basic	38,978		38,793		38,934		38,832
	Unvested restricted stock units	74		96		125		130
	Stock options	29		106		43		122
	Weighted average common shares outstanding – Diluted	39,081		38,995		39,102		39,084
	No shares were considered anti-dilutive during the periods reported.

Derivative_Instruments

Derivative Instruments

9 Months Ended

Sep. 30, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

'

Derivative Instruments

'

7

Derivative Instruments

The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed by using derivative instruments is commodity price risk. The Company enters into put and call option contracts related to the Company’s commodity price risk, which are based on the wholesale price of gasoline and retail price of diesel fuel and settle on a monthly basis. These put and call option contracts, or fuel price derivative instruments, are designed to reduce the volatility of the Company’s cash flows associated with its fuel price-related earnings exposure in North America. In 2010, the Company entered into an interest rate swap arrangement designed as a cash flow hedge to reduce a portion of the variability of the interest payments under the existing credit agreement borrowings. The interest rate swap agreement expired in March of 2012.

Accounting guidance requires companies to recognize all derivative instruments as either assets or liabilities at fair value in the statement of financial position. The Company designates interest rate swap arrangements as cash flow hedges of the forecasted interest payments on a portion of its variable-rate credit agreement. The Company’s fuel price derivative instruments do not qualify for hedge accounting treatment under current guidance, and therefore, no such hedging designation has been made. Because the derivatives are either accounting or economic hedges of operational exposures, cash flows from the settlement of such contracts are included in “Cash flows from operating activities” on the condensed consolidated statements of cash flows.

Cash Flow Hedges

For derivative instruments that are designated and qualify as a cash flow hedge, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current earnings. As of September 30, 2013, the Company had no outstanding cash flow hedges.

Derivatives Not Designated as Hedging Instruments

For derivative instruments that are not designated as hedging instruments, the gain or loss on the derivative is recognized in current earnings. As of September 30, 2013, the Company had the following put and call option contracts which settle on a monthly basis:

Aggregate

Notional

Amount

(gallons) (a)

Fuel price derivative instruments – unleaded fuel

Option contracts settling October 2013 – March 2015

36,953

Fuel price derivative instruments – diesel

Option contracts settling October 2013 – March 2015

17,402

Total fuel price derivative instruments

54,355

(a)

The settlement of the put and call option contracts is based upon the New York Mercantile Exchange’s New York Harbor Reformulated Gasoline Blendstock for Oxygen Blending and the U.S. Department of Energy’s weekly retail on-highway diesel fuel price for the month.

The following table presents information on the location and amounts of derivative fair values in the condensed consolidated balance sheets:

Derivatives Classified as Assets

Derivatives Classified as Liabilities

30-Sep-13

31-Dec-12

30-Sep-13

31-Dec-12

Balance

Fair

Balance

Fair

Balance

Fair

Balance

Fair

Sheet

Value

Sheet

Value

Sheet

Value

Sheet

Value

Location

Location

Location

Location

Derivatives Not Designated as Hedging Instruments

Commodity contracts

Fuel price

$

488

Fuel price

—

Fuel price

$

983

Fuel price

$

1,729

derivatives,

derivatives,

derivatives,

derivatives,

at fair value

at fair value

at fair value

at fair value

The following tables present information on the location and amounts of derivative gains and losses in the condensed consolidated statements of income:

Amount of Gain or (Loss)

Recognized in

Income on Derivative

Derivatives Not Designated as Hedging Instruments

Location of Gain or (Loss)

Three months ended September 30,

Recognized in

Income on Derivative

2013

2012

Commodity contracts

Net realized and unrealized loss on fuel price derivatives

$

(3,640

)

$

(14,026

)

Amount of Gain or

Location of Gain or

Amount of Gain

Location of Gain or

Amount of Gain or

(Loss) Recognized in

(Loss) Reclassified

or (Loss)

(Loss) Recognized in

(Loss) Recognized in

OCI on Derivative

from Accumulated

Reclassified

Income on Derivative

Income on  Derivative

(Effective

OCI into Income

from

(Ineffective  Portion

(Ineffective Portion

Portion) (a)

(Effective  Portion)

Accumulated

and Amount Excluded

and Amount

OCI  into

from Effectiveness

Excluded from

Income

Testing) (b)

Effectiveness Testing)

(Effective

Portion)

Derivatives in Cash Flow Hedging

Nine months ended September 30,

Nine months ended September 30,

Nine months ended September 30,

Relationships

2013

2012

2013

2012

2013

2012

Interest rate contracts

$

—

$

60

Financing interest expense

$

—

$

(109

)

Financing interest expense

$

—

$

—

Location of Gain or

Amount of Gain or

(Loss) Recognized in

(Loss) Recognized in

Income on Derivative

Income on  Derivative

Nine months ended September 30,

Derivatives Not Designated as Hedging Instruments

2013

2012

Commodity contracts

Net realized and unrealized loss on fuel price derivatives

$

(2,781

)

$

(12,046

)

(a)

The amount of gain or (loss) recognized in other comprehensive income ("OCI") on the Company’s interest rate swap arrangements has been recorded net of tax impact of $35 in 2012.

(b)

No ineffectiveness was reclassified into earnings nor was any amount excluded from effectiveness testing.

Financing_Debt

Financing Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Financing Debt	'
	8	Financing Debt
	2013 Credit Agreement
	On January 18, 2013, the Company entered into an amended and restated credit agreement (the “2013 Credit Agreement”), among the Company and a syndicate of lenders. The 2013 Credit Agreement provides for a five-year amortizing $300,000 term loan facility, and a five-year $800,000 secured revolving credit facility with a $150,000 sub-limit for letters of credit. The indebtedness covenant under the 2013 Credit Agreement requires that the Company reduce the revolving commitments under the 2013 Credit Agreement on a dollar-for-dollar basis to the extent that the Company issued more than $300,000 in principal amount of senior or senior subordinated notes of the Company. Subject to certain conditions, including obtaining relevant commitments, the Company has the option to increase the facility by up to an additional $100,000.
	The 2013 Credit Agreement replaced the 2011 Credit Agreement, dated as of May 23, 2011. The 2013 Credit Agreement increased the outstanding amount of the term loan from $185,000 to $300,000 and increased the amount of the revolving loan from $700,000 to $800,000. On January 30, 2013, the revolving loan commitment under the 2013 Credit Agreement was reduced to $700,000. The reduction was required due to the completion of the $400,000, 4.75 percent senior notes due in 2023, described below.
	$400 Million Note Offering
	On January 18, 2013, the Company completed a $400,000 offering in aggregate principal amount of 4.75 percent senior notes due in 2023 (the “Notes”) at an issue price of 100.0 percent of the principal amount, plus accrued interest, from January 18, 2013, in a private placement for resale to “qualified institutional buyers” as defined in Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), and in offshore transactions pursuant to Regulation S under the Securities Act. The Notes were issued pursuant to an indenture dated as of January 18, 2013 (the “Indenture”) among the Company, the guarantors listed therein, and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”). The Notes mature on February 1, 2023, and interest accrues at the rate of 4.75 percent per annum. Interest is payable semiannually in arrears on February 1 and August 1 of each year, commencing on August 1, 2013.
	The Notes are guaranteed on a senior unsecured basis by each of the Company’s restricted subsidiaries and each of the Company’s regulated subsidiaries that guarantees the Company’s 2013 Credit Agreement, which, as of the issue date, consisted of four of the Company’s restricted subsidiaries. WEX Bank, which represents a substantial amount of the Company’s operations, is not a guarantor and is not subject to many of the restrictive covenants in the indenture governing the Notes.
	The Notes and guarantees described above are general senior unsecured obligations ranking equally with the Company’s existing and future senior debt, senior in right of payment to all of the Company’s subordinated debt, and effectively junior in right of payment to all of the Company’s existing and future secured debt, including the Company’s 2013 Credit Agreement, to the extent of the value of the collateral securing such debt. In addition, the Notes and the guarantees are structurally subordinated to all liabilities of the Company’s subsidiaries that are not guarantors, including WEX Bank.
	Prior to February 1, 2016, the Company may, subject to certain conditions, redeem up to 35 percent of the Notes from the proceeds of certain equity offerings at a redemption price of 104.75 percent of the principal amount, plus accrued and unpaid interest, if any, to, but excluding, the date of redemption.
	Prior to February 1, 2018, the Company may redeem the Notes, in whole or in part, at a redemption price equal to 100.0 percent of the principal amount of such Notes redeemed plus a “make-whole” premium (as described in the Indenture), together with any accrued and unpaid interest up to the date of redemption.
	At any time on or after February 1, 2018, the Company may redeem the Notes, in whole or in part, at the following redemption prices (expressed as a percentage of principal amount of the Notes), plus accrued and unpaid interest, if any, to, but excluding, the date of redemption if redeemed during the twelve month period beginning on February 1 of the following years:
	Years beginning on February 1		Percentage of Principal
			Amount of Notes
	2018		102.375
	2019		101.583
	2020		100.792
	2021 and thereafter		100
	Upon the occurrence of a change in control of the Company (as described in the Indenture), the Company must offer to repurchase the Notes at 101 percent of the principal amount of the Notes, plus accrued and unpaid interest up to the date of repurchase.
	The Indenture contains covenants that, among other things, limit the Company’s ability and the ability of its restricted subsidiaries and, in certain limited circumstances, WEX Bank and the Company’s other regulated subsidiaries, to (i) incur additional debt, (ii) pay dividends or make other distributions on, redeem or repurchase capital stock, or make investments or other restricted payments, (iii) enter into transactions with affiliates, (iv) dispose of assets or issue stock of restricted subsidiaries or regulated subsidiaries, (v) create liens on assets, or (vi) effect a consolidation or merger or sell all, or substantially all, of the Company’s assets.
	These covenants are subject to important exceptions and qualifications. At any time that the Notes are rated investment grade, which is not currently the case, and subject to certain conditions, certain covenants will be suspended with respect to the Notes. WEX Bank and the Company’s other regulated subsidiaries will not be subject to some of the restrictive covenants in the Indenture that place limitations on the Company and its restricted subsidiaries’ actions, and where WEX Bank and the Company’s regulated subsidiaries are subject to covenants, there are significant exceptions and limitations on the application of those covenants to WEX Bank and the Company’s regulated subsidiaries.
	The Company used the net proceeds of this offering to repay the outstanding amount under the revolving portion of its 2013 Credit Agreement and to pay related fees and expenses and for general corporate purposes.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value	'
	9	Fair Value
	The Company holds mortgage-backed securities, fixed income and equity securities, derivatives and certain other financial instruments which are carried at fair value. The Company determines fair value based upon quoted prices when available or through the use of alternative approaches, such as model pricing, when market quotes are not readily accessible or available. In determining the fair value of the Company’s obligations, various factors are considered, including: closing exchange or over-the-counter market price quotations; time value and volatility factors underlying options and derivatives; price activity for equivalent instruments; and the Company’s own credit standing.
	These valuation techniques may be based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumptions. These two types of inputs create the following fair value hierarchy:
	•	Level 1 – Quoted prices for identical instruments inactive markets.
	•	Level 2 – Quoted prices for similar instruments inactive markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.
	•	Level 3 – Instruments whose significant value drivers are unobservable.
	The following table presents the Company’s assets and liabilities that are measured at fair value and the related hierarchy levels as of September 30, 2013:
						Fair Value Measurements
						at Reporting Date Using
		30-Sep-13				Quoted Prices				Significant				Significant
						in Active				Other				Unobservable
						Markets for				Observable				Inputs
						Identical				Inputs				(Level 3)
						Assets				(Level 2)
						(Level 1)
	Assets:
	Mortgage-backed securities	$	867			$	—			$	867			$	—
	Asset-backed securities	1,490				—				1,490				—
	Municipal bonds	535				—				535				—
	Equity securities	13,316				13,316				—				—
	Total available-for-sale securities	$	16,208			$	13,316			$	2,892			$	—
	Executive deferred compensation plan trust (a)	$	4,048			$	4,048			$	—			$	—
	Fuel price derivatives – unleaded fuel (b)	$	22			$	—			$	22			$	—
	Liabilities:
	Fuel price derivatives – diesel (b)	517				—				—				517
	(a)	The fair value of these instruments is recorded in other assets.
	(b)	The balance sheet presentation combines unleaded fuel and diesel fuel positions.
	The Notes outstanding at September 30, 2013, have a carrying value of $400,000 and fair value of $360,000. The fair value is based on market rates for the issuance of debt.
	The following table presents the Company’s assets and liabilities that are measured at fair value and the related hierarchy levels as of December 31, 2012:
						Fair Value Measurements
						at Reporting Date Using
		31-Dec-12				Quoted Prices				Significant				Significant
						in Active				Other				Unobservable
						Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Assets:
	Mortgage-backed securities	$	1,839			$	—			$	1,839			$	—
	Asset-backed securities	1,654				—				1,654				—
	Municipal bonds	641				—				641				—
	Equity securities	12,216				12,216				—				—
	Total available-for-sale securities	$	16,350			$	12,216			$	4,134			$	—
	Executive deferred compensation plan trust (a)	$	2,921			$	2,921			$	—			$	—
	Liabilities:
	Fuel price derivatives – unleaded fuel (b)	$	1,622			$	—			$	1,622			$	—
	Fuel price derivatives – diesel (b)	107				—				—				107
	Total fuel price derivatives	$	1,729			$	—			$	1,622			$	107
	Contingent consideration (c)	$	313			—				—				$	313
	(a)	The fair value of these instruments is recorded in other assets.
	(b)	The balance sheet presentation combines unleaded fuel and diesel fuel positions.
	(c)	The fair value of the contingent consideration is recorded in accrued expenses.
	The following table presents a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the three months ended:
			September 30, 2013				30-Sep-12
			Fuel Price				Contingent				Fuel Price
			Derivatives –				Consideration				Derivatives –
			Diesel								Diesel
	Beginning balance		$	498			$	—			$	3,398
	Total (losses) and gains – realized/unrealized
	Included in earnings (a)		(1,015		)		—				(3,812		)
	Included in other comprehensive income		—				—				—
	Purchases, issuances and settlements		—				(991		)		—
	Transfers (in)/out of Level 3		—				—				—
	Ending balance		$	(517	)		$	(991	)		$	(414	)
(a)	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the three months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the three months ended September 30, 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.
The following table presents a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the nine months ended:
	30-Sep-13								30-Sep-12
	Contingent				Fuel Price				Contingent				Fuel Price
	Consideration				Derivatives –				Consideration				Derivatives –
					Diesel								Diesel
Beginning balance	$	(313	)		$	(107	)		$	(9,325	)		$	(25	)
Total (losses) and gains – realized/unrealized
Included in earnings (a)	(198		)		(410		)		839				(389		)
Included in other comprehensive income	—				—				—				—
Purchases, issuances and settlements	—				—				(991		)		—
Transfers (in)/out of Level 3	511				—				8,486				—
Ending balance	$	—			$	(517	)		$	(991	)		$	(414	)
(a)	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.
Available-for-sale securities and executive deferred compensation plan trust
When available, the Company uses quoted market prices to determine the fair value of available-for-sale securities; such items are classified in Level 1 of the fair-value hierarchy. These securities primarily consist of exchange-traded equity securities.
For mortgage-backed and asset-backed debt securities and bonds, the Company generally uses quoted prices for recent trading activity of assets with similar characteristics to the debt security or bond being valued. The securities and bonds priced using such methods are generally classified as Level 2.
Fuel price derivatives and interest rate swap arrangements
The majority of derivatives entered into by the Company are executed over-the-counter and are valued using internal valuation techniques as no quoted market prices exist for such instruments. The valuation technique and inputs depend on the type of derivative and the nature of the underlying instrument. The principal technique used to value these instruments is a comparison of the spot price of the underlying instrument to its related futures curve adjusted for the Company’s assumptions of volatility and present value, where appropriate. The fair values of derivative contracts reflect the expected cash the Company will pay or receive upon settlement of the respective contracts.
The key inputs depend upon the type of derivative and the nature of the underlying instrument and include interest rate yield curves, the spot price of the underlying instruments, volatility, and correlation. The item is placed in either Level 2 or Level 3 depending on the observability of the significant inputs to the model. Correlation and inputs with longer tenures are generally less observable.
Fuel price derivatives – diesel. The assumptions used in the valuation of the diesel fuel price derivatives use both observable and unobservable inputs. There is a lack of price transparency with respect to forward prices for diesel fuel. Such unobservable inputs are significant to the diesel fuel derivative contract valuation methodology.
Quantitative Information About Level 3 Fair Value Measurements. The significant unobservable inputs used in the fair value measurement of the Company’s diesel fuel price derivative instruments designated as Level 3 as of September 30, 2013, are as follows:
	Fair Value at				Valuation		Unobservable Input		Range
	September 30, 2013				Technique				$ per gallon
Fuel price derivatives – diesel	$	(517	)		Option model		Future retail price of diesel fuel after September 30, 2013		$3.71 – 3.94
Sensitivity to Changes in Significant Unobservable Inputs. As presented in the table above, the significant unobservable inputs used in the fair value measurement of the Company’s diesel fuel price derivative instruments are the future retail price of diesel fuel from the fourth quarter of 2013 through the first quarter of 2015. Significant changes in these unobservable inputs in isolation would result in a significant change in the fair value measurement.
Contingent consideration
The Company had classified its liability for contingent consideration related to its acquisition of UNIK within Level 3 of the fair value hierarchy because the fair value is determined using significant unobservable inputs, which include the projected revenues of UNIK over a four month period. These assumptions included assessing the probability of meeting certain milestones required to earn the contingent consideration.
During the second quarter of 2013, the Company determined a final payment of contingent consideration and increased the liability by $201. On June 30, 2013, the amount due was determined to be $511 and was paid on July 1, 2013.
The Company classified its liability for contingent consideration related to its acquisition of rapid! PayCard within Level 3 of the fair value hierarchy because the fair value was determined using significant unobservable inputs, which include the revenues of rapid! PayCard over a twelve month period ending on March 31, 2012. On March 31, 2012, the amount due was determined to be $8,486 and was paid on April 30, 2012.

Comprehensive_Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Comprehensive Income	'
	10	Comprehensive Income
	A reconciliation of comprehensive income for the three month period ended September 30, 2013 and 2012, is as follows:
		2013						2012
		Unrealized			Foreign			Unrealized		Foreign
		Gains and			Currency			Gains and		Currency
		Losses on			Items			Losses on		Items
		Available-						Available-
		for-Sale						for-Sale
		Securities						Securities
	Beginning balance	$	(222	)	$	(7,052	)	$	270	$	28,631
	Other comprehensive (loss) income	(73		)	7,684			44		9,006
	Ending balance	$	(295	)	$	632		$	314	$	37,637
	No amounts were reclassified from accumulated other comprehensive income in the periods presented.
	A reconciliation of comprehensive income for the nine month period ended September 30, 2013 and 2012, is as follows:
		2013						2012
		Unrealized			Foreign			Unrealized		Foreign
		Gains and			Currency			Gains and		Currency
		Losses on			Items			Losses on		Items
		Available-						Available-
		for-Sale						for-Sale
		Securities						Securities
	Beginning balance	$	197		$	37,182		$	200	$	30,448
	Other comprehensive (loss) income	(492		)	(36,550		)	114		7,189
	Ending balance	$	(295	)	$	632		$	314	$	37,637
	No amounts were reclassified from accumulated other comprehensive income in the periods presented.

Redeemable_noncontrolling_inte

Redeemable noncontrolling interest	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Redeemable noncontrolling interest	'
	11	Redeemable noncontrolling interest
	On August 30, 2012, the Company acquired a 51 percent ownership interest in UNIK, a provider of payroll cards in Brazil. Redeemable noncontrolling interest is measured at fair value at the date of acquisition. The redeemable noncontrolling interest is reported on the Company’s condensed consolidated balance sheets as “Redeemable noncontrolling interest."
	A reconciliation of redeemable noncontrolling interest for the three and nine month periods ended September 30, 2013 and September 30, 2012, is as follows:
		Three months ended					Nine months ended
		September 30,					September 30,
		2013			2012		2013		2012
	Balance, beginning of period	$	19,650		—		21,662		—
	Acquisition of subsidiary at fair value	—			21,904		—		21,904
	Net loss attributable to noncontrolling interest	(60		)	(14	)	(333	)	(14	)
	Currency translation adjustment	172			223		(1,567	)	223
	Ending balance	$	19,762		22,113		19,762		22,113

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	12	Stock-Based Compensation
	During the first quarter of 2013, the Company awarded restricted stock units and performance-based restricted stock units to employees under the 2010 Equity and Incentive Plan. Expense associated with the performance-based restricted stock units may increase or decrease due to changes in the probability of the Company achieving pre-established performance metrics. For the nine months ended September 30, 2013, total stock-based compensation expense recognized was approximately $6,882. As of September 30, 2013, total unrecognized compensation cost related to non-vested restricted stock units, and performance-based restricted stock units was approximately $10,606 to be recognized over the remaining vesting periods of these awards.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	13	Income Taxes
	On June 29, 2012, tax legislation was enacted in Australia that affected the tax deductibility of certain intangible assets. A tax charge of $31,083 was recorded in June of 2012 to reflect these tax legislation changes. The Company wrote-off an associated refund claim payable to the former shareholder of RD Card Holding Australia for $9,750, included in non-operating income. This payable was contingent on the receipt of the tax refunds generated by tax deductions associated with the amortization of the above mentioned intangible assets.
	Undistributed earnings of certain foreign subsidiaries of the Company amounted to $2,507 at September 30, 2013, and $1,756 at December 31, 2012. These earnings are considered to be indefinitely reinvested, and accordingly, no U.S. federal and state income taxes have been provided thereon. Upon distribution of these earnings in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries. The Company has determined that the amount of taxes attributable to these undistributed earnings is not practicably determinable.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	14	Commitments and Contingencies
	Litigation
	The Company is involved in pending litigation in the usual course of business. In the opinion of management, such litigation will not have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flows.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	15	Segment Information
	Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The operating segments are reviewed separately as each operating segment represents a strategic business unit that generally offers different products and serves different markets.
	The Company’s chief operating decision maker evaluates the operating results of the Company’s reportable segments based upon revenues and “adjusted net income,” which is defined by the Company as net income adjusted for fair value changes of derivative instruments, the amortization of purchased intangibles, the net impact of tax rate changes on the Company’s deferred tax asset and related changes in the tax-receivable agreement, deferred loan costs associated with the extinguishment of debt, certain non-cash asset impairment charges, the gains on the extinguishment of a portion of the tax receivable agreement and adjustments attributable to noncontrolling interest. These adjustments are reflected net of the tax impact.
	The Company operates in two reportable segments, Fleet Payment Solutions and Other Payment Solutions. The Fleet Payment Solutions segment provides customers with payment and transaction processing services specifically designed for the needs of vehicle fleet customers. This segment also provides information management services to those fleet customers. The Other Payment Solutions segment provides customers with a payment processing solution for their corporate purchasing and transaction monitoring needs. Revenue in this segment is derived from the Company’s corporate purchase cards, virtual and prepaid card products. The corporate purchase card products are used by businesses to facilitate purchases of products and to utilize the Company’s information management capabilities.
	Financing interest expense through the Company’s corporate debt, including the term loan and bond issuance, and net realized and unrealized losses on derivative instruments are allocated to the Fleet Payment Solutions segment in the computation of segment results for internal evaluation purposes. Total assets are not allocated to the segments.
	The following table presents the Company’s reportable segment results on an adjusted net income basis for the three months ended September 30, 2013 and 2012:
		Total			Operating			Depreciation			Provision for			Adjusted Net
		Revenues			Interest			and			Income Taxes			Income
					Expense			Amortization
	Three months ended September 30, 2013
	Fleet payment solutions	$	136,874		$	427		$	5,767		$	21,726		35,119
	Other payment solutions	54,651			549			342			7,577			15,303
	Total	$	191,525		$	976		$	6,109		$	29,303		50,422
	Three months ended September 30, 2012
	Fleet payment solutions	$	117,877		$	838		$	5,856		$	21,874		$	33,641
	Other payment solutions	43,090			404			441			5,589			8,394
	Total	$	160,967		$	1,242		$	6,297		$	27,463		$	42,035
	The following table presents the Company’s reportable segment results on an adjusted net income basis for the nine months ended September 30, 2013 and 2012:
		Total			Operating			Depreciation			Provision for			Adjusted Net
		Revenues			Interest			and			Income Taxes			Income
					Expense			Amortization
	Nine months ended September 30, 2013
	Fleet payment solutions	$	393,953		$	1,392		$	17,358		$	58,474		99,950
	Other payment solutions	141,227			1,813			1,346			17,128			29,840
	Total	$	535,180		$	3,205		$	18,704		$	75,602		129,790
	Nine months ended September 30, 2012
	Fleet payment solutions	$	341,709		$	2,685		$	17,699		$	56,027		$	94,169
	Other payment solutions	112,444			744			1,241			13,607			22,512
	Total	$	454,153		$	3,429		$	18,940		$	69,634		$	116,681
	The following table reconciles adjusted net income to net income:
		Three months ended						Nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Adjusted net income WEX Inc.	$	50,422		$	42,035		$	129,790		$	116,681
	Unrealized (loss) gains on fuel price derivatives	(2,733		)	(12,849		)	1,234			(1,841		)
	Amortization of acquired intangible assets	(8,051		)	(5,411		)	(24,564		)	(15,481		)
	Goodwill impairment	—			(16,171		)	—			(16,171		)
	Deferred loan costs associated with the extinguishment of debt	—			—			(1,004		)	—
	Non-cash adjustments related to tax receivable agreement	150			—			150			—
	Change in tax refund due to former shareholders of RD Card Holding Australia	—			—			—			9,750
	Other adjustments related to Fleet One acquisition	658			—			658			—
	ANI adjustments attributable to noncontrolling interest	313			77			971			77
	Tax impact	3,079			6,617			7,505			(25,146		)
	Net earnings attributable to WEX Inc.	$	43,838		$	14,298		$	114,740		$	67,869
	The tax impact of the foregoing adjustments is the difference between the Company’s U.S. GAAP tax provision and a pro forma tax provision based upon the Company’s adjusted net income before taxes. The methodology utilized for calculating the Company’s adjusted net income tax provision is the same methodology utilized in calculating the Company’s U.S. GAAP tax provision.

Business_Acquisitions_Tables

Business Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2013
CorporatePay	'
Business Acquisition [Line Items]	'
Summary of Allocation of Purchase Price to Assets and Liabilities Acquired	'
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Consideration paid (net of cash)	$	27,783
	Less:
	Accounts receivable	1,585
	Accounts payable	(629		)
	Other tangible liabilities, net	(4,040		)
	Acquired software(a)	8,233
	Customer relationships(b)	1,614
	Trademarks and trade name(c)	1,453
	Recorded goodwill	$	19,567
	(a)	Weighted average life – 6.2 years.
	(b)	Weighted average life – 6.3 years.
	(c)	Weighted average life – 5.3 years.
UNIK	'
Business Acquisition [Line Items]	'
Summary of Allocation of Purchase Price to Assets and Liabilities Acquired	'
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Total UNIK value	$	44,701
	Less: Redeemable noncontrolling interest	21,904
	Total purchase price (includes estimated earn out of $991)	$	22,797
	Less:
	Cash	1,566
	Accounts receivable	11,726
	Accounts payable	(12,640		)
	Other tangible liabilities, net	(36,866		)
	Acquired software(a)	14,193
	Customer relationships(b)	15,171
	Trademarks and trade name(c)	1,272
	Recorded goodwill	$	28,375
	(a)	Weighted average life – 6.2 years.
	(b)	Weighted average life – 5.9 years.
	(c)	Weighted average life – 5.5 years.
Fleet One	'
Business Acquisition [Line Items]	'
Summary of Allocation of Purchase Price to Assets and Liabilities Acquired	'
	The following is a summary of the allocation of the purchase price to the assets and liabilities acquired:
	Consideration paid (net of cash)	$	376,258
	Less:
	Accounts receivable	152,527
	Accounts payable	(151,647		)
	Other tangible liabilities, net	(693		)
	Acquired software(a)	35,000
	Customer relationships(b)	74,000
	Trademarks and trade name(c)	4,000
	Recorded goodwill	$	263,071
	(a)	Weighted average life – 6.7 years.
	(b)	Weighted average life – 5.5 years.
	(c)	Weighted average life – 5.5 years.

Reserves_for_Credit_Losses_Tab

Reserves for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Aging of Accounts Receivable	'
	The following table presents the Company’s aging of accounts receivable:
		Age Analysis of Past Due Financing Receivables, Gross
		as of September 30, 2013, and September 30, 2012
		Current			30-59 Days			60-89 Days			Greater			Total
		and Less			Past Due			Past Due			Than
		Than 30									90 Days
		Days Past									Past
		Due									Due
	2013
	Accounts receivable, trade	$	1,852,563		$	50,691		$	10,718		$	8,596		$	1,922,568
	Percent of total	96.4		%	2.6		%	0.6		%	0.4		%
	2012
	Accounts receivable, trade	$	1,595,483		$	32,031		$	6,123		$	7,130		$	1,640,767
	Percent of total	97.2		%	2		%	0.4		%	0.4		%
Changes in Reserves for Credit Losses Related to Accounts Receivable	'
	The following table presents changes in reserves for credit losses related to accounts receivable:
		Nine months ended
		September 30,
		2013			2012
	Balance, beginning of period	$	11,709		$	11,526
	Provision for credit losses	13,686			14,874
	Charge-offs	(21,150		)	(20,397		)
	Recoveries of amounts previously charged-off	5,031			4,065
	Currency translation	(322		)	—
	Balance, end of period	$	8,954		$	10,068

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in Goodwill	'
	The changes in goodwill during the first nine months of 2013 were as follows:
		Fleet Payment Solutions Segment			Other			Total
					Payment
					Solutions
					Segment
	Gross goodwill, January 1, 2013, as adjusted	$	779,654		$	85,840		$	865,494
	Impact of foreign currency translation	(21,123		)	(2,556		)	(23,679		)
	Gross goodwill, September 30, 2013	758,531			83,284			841,815
	Accumulated impairment, September 30, 2013	(1,337		)	(16,171		)	(17,508		)
	Net goodwill, September 30, 2013	$	757,194		$	67,113		$	824,307
Changes in Other Intangible Assets	'
	The changes in other intangible assets during the first nine months of 2013 were as follows:
		Net			Transfer from indefinite-lived intangible assets to definite-lived intangible assets			Amortization			Impact of			Net Carrying
		Carrying									foreign			Amount,
		Amount,									currency			September 30,
		January 1,									translation			2013
		2013
		(As adjusted)
	Definite-lived intangible assets
	Acquired software	$	71,343		$	—		$	(6,350	)	$	(1,584	)	$	63,409
	Customer relationships	150,290			—			(17,264		)	(5,819		)	127,207
	Patent	2,365			—			(341		)	(176		)	1,848
	Trade names	7,407			2,421			(609		)	(116		)	9,103
	Indefinite-lived intangible assets													—
	Trademarks and trade names	10,545			(2,421		)	—			(617		)	7,507
	Total	$	241,950		$	—		$	(24,564	)	$	(8,312	)	$	209,074
Estimated Amortization Expense Related to Definite Lived Intangible Assets	'
	The following table presents the estimated amortization expense related to the definite-lived intangible assets listed above for the remainder of 2013 and for each of the five succeeding fiscal years:
	Estimated Amortization Expense
	Remaining 2013	$	8,188
	2014	$	31,541
	2015	$	28,918
	2016	$	25,360
	2017	$	21,625
	2018	$	18,606
Other Intangible Assets	'
	Other intangible assets consist of the following:
		30-Sep-13									31-Dec-12
		Gross			Accumulated			Net Carrying			Gross			Accumulated			Net Carrying
		Carrying			Amortization			Amount			Carrying			Amortization			Amount
		Amount									Amount
	Definite-lived intangible assets
	Acquired software	$	84,023		$	(20,614	)	$	63,409		$	86,527		$	(15,184	)	$	71,343
	Non-compete agreement	100			(100		)	—			100			(100		)	—
	Customer relationships	192,846			(65,639		)	127,207			202,061			(51,771		)	150,290
	Patent	3,083			(1,235		)	1,848			3,430			(1,065		)	2,365
	Trademarks and trade names	10,137			(1,034		)	9,103			7,827			(420		)	7,407
		$	290,189		$	(88,622	)	201,567			$	299,945		$	(68,540	)	231,405
	Indefinite-lived intangible assets
	Trademarks and trade names							7,507									10,545
	Total							$	209,074								$	241,950

Earnings_per_Share_Tables

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Reconciliation of Income and Share Data Used in Basic and Diluted Earnings Per Share Computations	'
	The following is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the three and nine months ended September 30, 2013 and 2012:
		Three months ended				Nine months ended
		September 30,				September 30,
		2013		2012		2013		2012
	Net earnings attributable to WEX Inc. available for common stockholders – Basic and Diluted	$	43,838	$	14,298	$	114,740	$	67,869
	Weighted average common shares outstanding – Basic	38,978		38,793		38,934		38,832
	Unvested restricted stock units	74		96		125		130
	Stock options	29		106		43		122
	Weighted average common shares outstanding – Diluted	39,081		38,995		39,102		39,084

Derivative_Instruments_Tables

Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

'

Put and Call Option Contracts

'

As of September 30, 2013, the Company had the following put and call option contracts which settle on a monthly basis:

Aggregate

Notional

Amount

(gallons) (a)

Fuel price derivative instruments – unleaded fuel

Option contracts settling October 2013 – March 2015

36,953

Fuel price derivative instruments – diesel

Option contracts settling October 2013 – March 2015

17,402

Total fuel price derivative instruments

54,355

(a)

The settlement of the put and call option contracts is based upon the New York Mercantile Exchange’s New York Harbor Reformulated Gasoline Blendstock for Oxygen Blending and the U.S. Department of Energy’s weekly retail on-highway diesel fuel price for the month.

Location and Amounts of Derivative Fair Values in Condensed Consolidated Balance Sheets

'

The following table presents information on the location and amounts of derivative fair values in the condensed consolidated balance sheets:

Derivatives Classified as Assets

Derivatives Classified as Liabilities

30-Sep-13

31-Dec-12

30-Sep-13

31-Dec-12

Balance

Fair

Balance

Fair

Balance

Fair

Balance

Fair

Sheet

Value

Sheet

Value

Sheet

Value

Sheet

Value

Location

Location

Location

Location

Derivatives Not Designated as Hedging Instruments

Commodity contracts

Fuel price

$

488

Fuel price

—

Fuel price

$

983

Fuel price

$

1,729

derivatives,

derivatives,

derivatives,

derivatives,

at fair value

at fair value

at fair value

at fair value

Location and Amounts of Derivative Gains and Losses in Condensed Consolidated Statements of Income

'

The following tables present information on the location and amounts of derivative gains and losses in the condensed consolidated statements of income:

Amount of Gain or (Loss)

Recognized in

Income on Derivative

Derivatives Not Designated as Hedging Instruments

Location of Gain or (Loss)

Three months ended September 30,

Recognized in

Income on Derivative

2013

2012

Commodity contracts

Net realized and unrealized loss on fuel price derivatives

$

(3,640

)

$

(14,026

)

Amount of Gain or

Location of Gain or

Amount of Gain

Location of Gain or

Amount of Gain or

(Loss) Recognized in

(Loss) Reclassified

or (Loss)

(Loss) Recognized in

(Loss) Recognized in

OCI on Derivative

from Accumulated

Reclassified

Income on Derivative

Income on  Derivative

(Effective

OCI into Income

from

(Ineffective  Portion

(Ineffective Portion

Portion) (a)

(Effective  Portion)

Accumulated

and Amount Excluded

and Amount

OCI  into

from Effectiveness

Excluded from

Income

Testing) (b)

Effectiveness Testing)

(Effective

Portion)

Derivatives in Cash Flow Hedging

Nine months ended September 30,

Nine months ended September 30,

Nine months ended September 30,

Relationships

2013

2012

2013

2012

2013

2012

Interest rate contracts

$

—

$

60

Financing interest expense

$

—

$

(109

)

Financing interest expense

$

—

$

—

Location of Gain or

Amount of Gain or

(Loss) Recognized in

(Loss) Recognized in

Income on Derivative

Income on  Derivative

Nine months ended September 30,

Derivatives Not Designated as Hedging Instruments

2013

2012

Commodity contracts

Net realized and unrealized loss on fuel price derivatives

$

(2,781

)

$

(12,046

)

(a)

The amount of gain or (loss) recognized in other comprehensive income ("OCI") on the Company’s interest rate swap arrangements has been recorded net of tax impact of $35 in 2012.

(b)

No ineffectiveness was reclassified into earnings nor was any amount excluded from effectiveness testing.

Financing_Debt_Tables

Financing Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Redemption Prices Expressed as a Percentage of Principal Amount of the Notes	'
	At any time on or after February 1, 2018, the Company may redeem the Notes, in whole or in part, at the following redemption prices (expressed as a percentage of principal amount of the Notes), plus accrued and unpaid interest, if any, to, but excluding, the date of redemption if redeemed during the twelve month period beginning on February 1 of the following years:
	Years beginning on February 1	Percentage of Principal
		Amount of Notes
	2018	102.375
	2019	101.583
	2020	100.792
	2021 and thereafter	100

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Assets And Liabilities Measured At Fair Value	'
	The following table presents the Company’s assets and liabilities that are measured at fair value and the related hierarchy levels as of December 31, 2012:
						Fair Value Measurements
						at Reporting Date Using
		31-Dec-12				Quoted Prices				Significant				Significant
						in Active				Other				Unobservable
						Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Assets:
	Mortgage-backed securities	$	1,839			$	—			$	1,839			$	—
	Asset-backed securities	1,654				—				1,654				—
	Municipal bonds	641				—				641				—
	Equity securities	12,216				12,216				—				—
	Total available-for-sale securities	$	16,350			$	12,216			$	4,134			$	—
	Executive deferred compensation plan trust (a)	$	2,921			$	2,921			$	—			$	—
	Liabilities:
	Fuel price derivatives – unleaded fuel (b)	$	1,622			$	—			$	1,622			$	—
	Fuel price derivatives – diesel (b)	107				—				—				107
	Total fuel price derivatives	$	1,729			$	—			$	1,622			$	107
	Contingent consideration (c)	$	313			—				—				$	313
	(a)	The fair value of these instruments is recorded in other assets.
	(b)	The balance sheet presentation combines unleaded fuel and diesel fuel positions.
	(c)	The fair value of the contingent consideration is recorded in accrued expenses.
	The following table presents the Company’s assets and liabilities that are measured at fair value and the related hierarchy levels as of September 30, 2013:
						Fair Value Measurements
						at Reporting Date Using
		30-Sep-13				Quoted Prices				Significant				Significant
						in Active				Other				Unobservable
						Markets for				Observable				Inputs
						Identical				Inputs				(Level 3)
						Assets				(Level 2)
						(Level 1)
	Assets:
	Mortgage-backed securities	$	867			$	—			$	867			$	—
	Asset-backed securities	1,490				—				1,490				—
	Municipal bonds	535				—				535				—
	Equity securities	13,316				13,316				—				—
	Total available-for-sale securities	$	16,208			$	13,316			$	2,892			$	—
	Executive deferred compensation plan trust (a)	$	4,048			$	4,048			$	—			$	—
	Fuel price derivatives – unleaded fuel (b)	$	22			$	—			$	22			$	—
	Liabilities:
	Fuel price derivatives – diesel (b)	517				—				—				517
	(a)	The fair value of these instruments is recorded in other assets.
	(b)	The balance sheet presentation combines unleaded fuel and diesel fuel positions.
Reconciliation Of Beginning And Ending Balances For Assets And Liabilities Measured At Fair Value On Recurring Basis Using Significant Unobservable Inputs	'
	The following table presents a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the three months ended:
			September 30, 2013				30-Sep-12
			Fuel Price				Contingent				Fuel Price
			Derivatives –				Consideration				Derivatives –
			Diesel								Diesel
	Beginning balance		$	498			$	—			$	3,398
	Total (losses) and gains – realized/unrealized
	Included in earnings (a)		(1,015		)		—				(3,812		)
	Included in other comprehensive income		—				—				—
	Purchases, issuances and settlements		—				(991		)		—
	Transfers (in)/out of Level 3		—				—				—
	Ending balance		$	(517	)		$	(991	)		$	(414	)
	(a)	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the three months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the three months ended September 30, 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.
	The following table presents a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the nine months ended:
		30-Sep-13								30-Sep-12
		Contingent				Fuel Price				Contingent				Fuel Price
		Consideration				Derivatives –				Consideration				Derivatives –
						Diesel								Diesel
	Beginning balance	$	(313	)		$	(107	)		$	(9,325	)		$	(25	)
	Total (losses) and gains – realized/unrealized
	Included in earnings (a)	(198		)		(410		)		839				(389		)
	Included in other comprehensive income	—				—				—				—
	Purchases, issuances and settlements	—				—				(991		)		—
	Transfers (in)/out of Level 3	511				—				8,486				—
	Ending balance	$	—			$	(517	)		$	(991	)		$	(414	)
	(a)	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.
Quantitative Information About Level Three Fair Value Measurements	'
	The significant unobservable inputs used in the fair value measurement of the Company’s diesel fuel price derivative instruments designated as Level 3 as of September 30, 2013, are as follows:
		Fair Value at				Valuation		Unobservable Input		Range
		September 30, 2013				Technique				$ per gallon
	Fuel price derivatives – diesel	$	(517	)		Option model		Future retail price of diesel fuel after September 30, 2013		$3.71 – 3.94

Comprehensive_Income_Tables

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Reconciliation of Comprehensive Income	'
	A reconciliation of comprehensive income for the three month period ended September 30, 2013 and 2012, is as follows:
		2013						2012
		Unrealized			Foreign			Unrealized		Foreign
		Gains and			Currency			Gains and		Currency
		Losses on			Items			Losses on		Items
		Available-						Available-
		for-Sale						for-Sale
		Securities						Securities
	Beginning balance	$	(222	)	$	(7,052	)	$	270	$	28,631
	Other comprehensive (loss) income	(73		)	7,684			44		9,006
	Ending balance	$	(295	)	$	632		$	314	$	37,637
	No amounts were reclassified from accumulated other comprehensive income in the periods presented.
	A reconciliation of comprehensive income for the nine month period ended September 30, 2013 and 2012, is as follows:
		2013						2012
		Unrealized			Foreign			Unrealized		Foreign
		Gains and			Currency			Gains and		Currency
		Losses on			Items			Losses on		Items
		Available-						Available-
		for-Sale						for-Sale
		Securities						Securities
	Beginning balance	$	197		$	37,182		$	200	$	30,448
	Other comprehensive (loss) income	(492		)	(36,550		)	114		7,189
	Ending balance	$	(295	)	$	632		$	314	$	37,637

Redeemable_noncontrolling_inte1

Redeemable noncontrolling interest (Tables)	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Redeemable Noncontrolling Interest	'
	A reconciliation of redeemable noncontrolling interest for the three and nine month periods ended September 30, 2013 and September 30, 2012, is as follows:
		Three months ended					Nine months ended
		September 30,					September 30,
		2013			2012		2013		2012
	Balance, beginning of period	$	19,650		—		21,662		—
	Acquisition of subsidiary at fair value	—			21,904		—		21,904
	Net loss attributable to noncontrolling interest	(60		)	(14	)	(333	)	(14	)
	Currency translation adjustment	172			223		(1,567	)	223
	Ending balance	$	19,762		22,113		19,762		22,113

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Reportable Segment Results	'
	The following table presents the Company’s reportable segment results on an adjusted net income basis for the three months ended September 30, 2013 and 2012:
		Total			Operating			Depreciation			Provision for			Adjusted Net
		Revenues			Interest			and			Income Taxes			Income
					Expense			Amortization
	Three months ended September 30, 2013
	Fleet payment solutions	$	136,874		$	427		$	5,767		$	21,726		35,119
	Other payment solutions	54,651			549			342			7,577			15,303
	Total	$	191,525		$	976		$	6,109		$	29,303		50,422
	Three months ended September 30, 2012
	Fleet payment solutions	$	117,877		$	838		$	5,856		$	21,874		$	33,641
	Other payment solutions	43,090			404			441			5,589			8,394
	Total	$	160,967		$	1,242		$	6,297		$	27,463		$	42,035
	The following table presents the Company’s reportable segment results on an adjusted net income basis for the nine months ended September 30, 2013 and 2012:
		Total			Operating			Depreciation			Provision for			Adjusted Net
		Revenues			Interest			and			Income Taxes			Income
					Expense			Amortization
	Nine months ended September 30, 2013
	Fleet payment solutions	$	393,953		$	1,392		$	17,358		$	58,474		99,950
	Other payment solutions	141,227			1,813			1,346			17,128			29,840
	Total	$	535,180		$	3,205		$	18,704		$	75,602		129,790
	Nine months ended September 30, 2012
	Fleet payment solutions	$	341,709		$	2,685		$	17,699		$	56,027		$	94,169
	Other payment solutions	112,444			744			1,241			13,607			22,512
	Total	$	454,153		$	3,429		$	18,940		$	69,634		$	116,681
Reconciliation of Adjusted Net Income To Net Income	'
	The following table reconciles adjusted net income to net income:
		Three months ended						Nine months ended
		September 30,						September 30,
		2013			2012			2013			2012
	Adjusted net income WEX Inc.	$	50,422		$	42,035		$	129,790		$	116,681
	Unrealized (loss) gains on fuel price derivatives	(2,733		)	(12,849		)	1,234			(1,841		)
	Amortization of acquired intangible assets	(8,051		)	(5,411		)	(24,564		)	(15,481		)
	Goodwill impairment	—			(16,171		)	—			(16,171		)
	Deferred loan costs associated with the extinguishment of debt	—			—			(1,004		)	—
	Non-cash adjustments related to tax receivable agreement	150			—			150			—
	Change in tax refund due to former shareholders of RD Card Holding Australia	—			—			—			9,750
	Other adjustments related to Fleet One acquisition	658			—			658			—
	ANI adjustments attributable to noncontrolling interest	313			77			971			77
	Tax impact	3,079			6,617			7,505			(25,146		)
	Net earnings attributable to WEX Inc.	$	43,838		$	14,298		$	114,740		$	67,869

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Basis Of Preparation [Line Items]	'	'
Increase (decrease) in total assets	$3,657,457	$3,131,865
Increase (decrease) in total liabilities	2,755,829	2,292,272
Increase (decrease) in total liabilities and stockholders' equity	3,657,457	3,131,865
Notes outstanding, carrying value	400,000	0
Notes outstanding, fair value	360,000	'
Restatement Adjustment - Error Correction	'	'
Basis Of Preparation [Line Items]	'	'
Increase (decrease) in deferred income tax assets	'	18,407
Increase (decrease) in total assets	'	18,407
Increase (decrease) in deferred tax liabilities	'	18,407
Increase (decrease) in total liabilities	'	18,407
Increase (decrease) in total liabilities and stockholders' equity	'	$18,407

Business_Acquisitions_Addition

Business Acquisitions - Additional Information (Detail)

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

11-May-12

11-May-12

Dec. 31, 2012

Aug. 30, 2012

Aug. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2012

Jun. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

In Thousands, unless otherwise specified

USD ($)

USD ($)

CorporatePay

CorporatePay

CorporatePay

CorporatePay

UNIK

UNIK

UNIK

UNIK

UNIK

UNIK

Fleet One

Fleet One

USD ($)

USD ($)

GBP (£)

Restatement Adjustment

USD ($)

BRL

USD ($)

USD ($)

Restatement Adjustment

Scenario, Revised

USD ($)

Restatement Adjustment

USD ($)

USD ($)

USD ($)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consideration paid

'

'

$27,783

$27,783

£ 17,000

'

'

'

$22,797

'

'

'

$376,258

'

Increase (decrease) accounts receivable

1,913,614

1,556,275

'

'

'

508

'

'

'

'

'

'

'

-47

Increase (decrease) in deferred income tax assets

'

'

'

'

'

-32

'

'

'

'

2,243

'

'

261

Increase (decrease) other intangible assets, net

209,074

241,950

'

'

'

140

'

'

'

'

'

'

'

'

Increase (decrease) goodwill

824,307

847,986

'

'

'

-247

'

'

'

'

4,355

'

'

-407

Increase (decrease) accrued expenses

79,754

67,419

'

'

'

369

'

'

'

'

6,598

'

'

-80

Increase (decrease) income taxes payable

14,228

10,038

'

'

'

'

'

'

'

'

'

'

'

-113

Percent of ownership interest acquired

'

'

'

'

'

'

51.00%

51.00%

'

'

'

'

'

'

Value of newly issued shares

'

'

'

'

'

'

22,800

44,800

'

'

'

'

'

'

Consideration for future performance milestones

'

'

'

'

'

'

1,000

2,000

991

'

'

511

'

'

Period to acquire remaining shares

'

'

'

'

'

'

'3 years

'3 years

'

'

'

'

'

'

Cash paid on acquisition of debt

'

'

'

'

'

'

'

'

'

19,600

'

'

'

'

Acquisition of debt unpaid

'

'

'

'

'

'

'

'

$6,764

'

'

'

'

'

Summary_of_Allocation_of_Purch

Summary of Allocation of Purchase Price to Assets and Liabilities Acquired (Detail)	Sep. 30, 2013		11-May-12	11-May-12	Sep. 30, 2013		Aug. 30, 2012	Aug. 30, 2012	Sep. 30, 2013
In Thousands, unless otherwise specified	CorporatePay		CorporatePay	CorporatePay	UNIK		UNIK	UNIK	Fleet One
	USD ($)		USD ($)	GBP (£)	USD ($)		USD ($)	BRL	USD ($)
Business Acquisition [Line Items]	'		'	'	'		'	'	'
Total UNIK value	'		'	'	$44,701		'	'	'
Less: Redeemable noncontrolling interest	'		'	'	21,904		'	'	'
Consideration paid (net of cash)	27,783		27,783	17,000	22,797		'	'	376,258
Estimated earn out	'		'	'	991		1,000	2,000	'
Cash	'		'	'	1,566		'	'	'
Accounts receivable	1,585		'	'	11,726		'	'	152,527
Accounts payable	-629		'	'	-12,640		'	'	-151,647
Other tangible liabilities, net	-4,040		'	'	-36,866		'	'	-693
Acquired software	8,233	[1]	'	'	14,193	[1]	'	'	35,000	[2]
Customer relationships	1,614	[3]	'	'	15,171	[4]	'	'	74,000	[5]
Trademarks and trade name	1,453	[6]	'	'	1,272	[5]	'	'	4,000	[5]
Recorded goodwill	$19,567		'	'	$28,375		'	'	$263,071
[1]	Weighted average life – 6.2 years.
[2]	Weighted average life – 6.7 years.
[3]	Weighted average life – 6.3 years.
[4]	Weighted average life – 5.9 years.
[5]	Weighted average life – 5.5 years.
[6]	Weighted average life – 5.3 years.

Summary_of_Allocation_of_Purch1

Summary of Allocation of Purchase Price to Assets and Liabilities Acquired (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2013
CorporatePay | Acquired Software	'
Business Acquisition [Line Items]	'
Weighted average life	'6 years 2 months 12 days
CorporatePay | Customer relationships	'
Business Acquisition [Line Items]	'
Weighted average life	'6 years 3 months 18 days
CorporatePay | Trademarks and trade names	'
Business Acquisition [Line Items]	'
Weighted average life	'5 years 3 months 18 days
UNIK | Acquired Software	'
Business Acquisition [Line Items]	'
Weighted average life	'6 years 2 months 12 days
UNIK | Customer relationships	'
Business Acquisition [Line Items]	'
Weighted average life	'5 years 10 months 24 days
UNIK | Trademarks and trade names	'
Business Acquisition [Line Items]	'
Weighted average life	'5 years 6 months
Fleet One | Acquired Software	'
Business Acquisition [Line Items]	'
Weighted average life	'6 years 8 months 12 days
Fleet One | Customer relationships	'
Business Acquisition [Line Items]	'
Weighted average life	'5 years 6 months
Fleet One | Trademarks and trade names	'
Business Acquisition [Line Items]	'
Weighted average life	'5 years 6 months

Reserves_for_Credit_Losses_Add

Reserves for Credit Losses - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Trade receivable payments terms	'30 days

Aging_of_Accounts_Receivable_D

Aging of Accounts Receivable (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Accounts receivable, trade, Current and Less Than 30 Days Past Due	$1,852,563	$1,595,483
Accounts receivable, trade, 30-59 Days Past Due	50,691	32,031
Accounts receivable, trade, 60-89 Days Past Due	10,718	6,123
Accounts receivable, trade, Greater Than 90 Days Past Due	8,596	7,130
Accounts receivable, trade, Total	$1,922,568	$1,640,767
Percent of total, Current and Less Than 30 Days Past Due	96.40%	97.20%
Percent of total, 30-59 Days Past Due	2.60%	2.00%
Percent of total, 60-89 Days Past Due	0.60%	0.40%
Percent of total, Greater Than 90 Days Past Due	0.40%	0.40%

Changes_in_Reserves_for_Credit

Changes in Reserves for Credit Losses Related to Accounts Receivable (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'
Balance, beginning of period	$11,709	$11,526
Provision for credit losses	13,686	14,874
Charge-offs	-21,150	-20,397
Recoveries of amounts previously charged-off	5,031	4,065
Currency translation	-322	0
Balance, end of period	$8,954	$10,068

Changes_In_Goodwill_Detail

Changes In Goodwill (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Goodwill [Roll Forward]	'	'
Gross goodwill, January 1, 2013, as adjusted	$865,494	'
Impact of foreign currency translation	-23,679	'
Gross goodwill, September 30, 2013	841,815	'
Accumulated impairment, September 30, 2013	-17,508	'
Net goodwill, September 30, 2013	824,307	847,986
Fleet Payment Solutions Segment	'	'
Goodwill [Roll Forward]	'	'
Gross goodwill, January 1, 2013, as adjusted	779,654	'
Impact of foreign currency translation	-21,123	'
Gross goodwill, September 30, 2013	758,531	'
Accumulated impairment, September 30, 2013	-1,337	'
Net goodwill, September 30, 2013	757,194	'
Other Payment Solutions Segment	'	'
Goodwill [Roll Forward]	'	'
Gross goodwill, January 1, 2013, as adjusted	85,840	'
Impact of foreign currency translation	-2,556	'
Gross goodwill, September 30, 2013	83,284	'
Accumulated impairment, September 30, 2013	-16,171	'
Net goodwill, September 30, 2013	$67,113	'

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'	'
Goodwill impairment	$0	$16,171	$0	$16,171
Trade names	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Finite-lived intangible asset, useful life	'10 years	'	'	'

Changes_in_Intangible_Assets_D

Changes in Intangible Assets (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Intangible Assets [Line Items]	'	'	'	'
Net Carrying Amount, Definite-lived intangible assets, January 1, 2013, as adjusted	'	'	$231,405	'
Net Carrying Amount, Other Intangible Assets, January 1, 2013, as adjusted	'	'	241,950	'
Amortization, Definite-lived intangible assets	-8,051	-5,411	-24,564	-15,481
Impact of foreign currency translation, Other Intangible Assets	'	'	-8,312	'
Net Carrying Amount, Definite-lived intangible assets, September 30, 2013	201,567	'	201,567	'
Net Carrying Amount, Other Intangible Assets, September 30, 2013	209,074	'	209,074	'
Trademarks and trade names	'	'	'	'
Other Intangible Assets [Line Items]	'	'	'	'
Transfer from indefinite-lived intangible assets to definite-lived intangible assets	'	'	-2,421	'
Net Carrying Amount, Indefinite-lived intangible assets, January 1, 2013, as adjusted	'	'	10,545	'
Impact of foreign currency translation, Indefinite-lived intangible assets	'	'	-617	'
Net Carrying Amount, Indefinite-lived intangible assets, September 30, 2013	7,507	'	7,507	'
Acquired software	'	'	'	'
Other Intangible Assets [Line Items]	'	'	'	'
Net Carrying Amount, Definite-lived intangible assets, January 1, 2013, as adjusted	'	'	71,343	'
Amortization, Definite-lived intangible assets	'	'	-6,350	'
Impact of foreign currency translation, Definite-lived intangible assets	'	'	-1,584	'
Net Carrying Amount, Definite-lived intangible assets, September 30, 2013	63,409	'	63,409	'
Customer relationships	'	'	'	'
Other Intangible Assets [Line Items]	'	'	'	'
Net Carrying Amount, Definite-lived intangible assets, January 1, 2013, as adjusted	'	'	150,290	'
Amortization, Definite-lived intangible assets	'	'	-17,264	'
Impact of foreign currency translation, Definite-lived intangible assets	'	'	-5,819	'
Net Carrying Amount, Definite-lived intangible assets, September 30, 2013	127,207	'	127,207	'
Patent	'	'	'	'
Other Intangible Assets [Line Items]	'	'	'	'
Net Carrying Amount, Definite-lived intangible assets, January 1, 2013, as adjusted	'	'	2,365	'
Amortization, Definite-lived intangible assets	'	'	-341	'
Impact of foreign currency translation, Definite-lived intangible assets	'	'	-176	'
Net Carrying Amount, Definite-lived intangible assets, September 30, 2013	1,848	'	1,848	'
Trade names	'	'	'	'
Other Intangible Assets [Line Items]	'	'	'	'
Net Carrying Amount, Definite-lived intangible assets, January 1, 2013, as adjusted	'	'	7,407	'
Transfer from indefinite-lived intangible assets to definite-lived intangible assets	'	'	2,421	'
Amortization, Definite-lived intangible assets	'	'	-609	'
Impact of foreign currency translation, Definite-lived intangible assets	'	'	-116	'
Net Carrying Amount, Definite-lived intangible assets, September 30, 2013	$9,103	'	$9,103	'

Estimated_Amortization_Expense

Estimated Amortization Expense Related to Definite Lived Intangible Assets (Detail) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'
Remaining 2013	$8,188
2014	31,541
2015	28,918
2016	25,360
2017	21,625
2018	$18,606

Other_Intangible_Assets_Detail

Other Intangible Assets (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	$290,189	$299,945
Accumulated Amortization, Definite-lived intangible assets	-88,622	-68,540
Net Carrying Amount, Definite-lived intangible assets	201,567	231,405
Other intangible assets, Net Carrying Amount	209,074	241,950
Acquired software	'	'
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	84,023	86,527
Accumulated Amortization, Definite-lived intangible assets	-20,614	-15,184
Net Carrying Amount, Definite-lived intangible assets	63,409	71,343
Non-compete agreement	'	'
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	100	100
Accumulated Amortization, Definite-lived intangible assets	-100	-100
Net Carrying Amount, Definite-lived intangible assets	0	0
Customer relationships	'	'
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	192,846	202,061
Accumulated Amortization, Definite-lived intangible assets	-65,639	-51,771
Net Carrying Amount, Definite-lived intangible assets	127,207	150,290
Patent	'	'
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	3,083	3,430
Accumulated Amortization, Definite-lived intangible assets	-1,235	-1,065
Net Carrying Amount, Definite-lived intangible assets	1,848	2,365
Trademarks and trade names	'	'
Other Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Definite-lived intangible assets	10,137	7,827
Accumulated Amortization, Definite-lived intangible assets	-1,034	-420
Net Carrying Amount, Definite-lived intangible assets	9,103	7,407
Net Carrying Amount, Indefinite-lived intangible assets	$7,507	$10,545

Reconciliation_of_Income_and_S

Reconciliation of Income and Share Data Used in Basic and Diluted Earnings Per Share Computations (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'	'	'
Net earnings attributable to WEX Inc. available for common stockholders – Basic and Diluted	$43,838	$14,298	$114,740	$67,869
Weighted average common shares outstanding – Basic	38,978	38,793	38,934	38,832
Unvested restricted stock units	74	96	125	130
Stock options	29	106	43	122
Weighted average common shares outstanding – Diluted	39,081	38,995	39,102	39,084

Put_and_Call_Option_Contracts_

Put and Call Option Contracts (Detail)	9 Months Ended
	Sep. 30, 2013
	gal
Derivative [Line Items]	'
Total fuel price derivative instruments, gallons	54,355,000	[1]
Unleaded Fuel	'
Derivative [Line Items]	'
Total fuel price derivative instruments, gallons	36,953,000	[1]
Diesel	'
Derivative [Line Items]	'
Total fuel price derivative instruments, gallons	17,402,000	[1]
[1]	The settlement of the put and call option contracts is based upon the New York Mercantile Exchange’s New York Harbor Reformulated Gasoline Blendstock for Oxygen Blending and the U.S. Department of Energy’s weekly retail on-highway diesel fuel price for the month.

Put_and_Call_Option_Contracts_1

Put and Call Option Contracts (Parenthetical) (Detail)	Sep. 30, 2013
Minimum | Unleaded Fuel	'
Derivative [Line Items]	'
Option contracts settlement date	'2013-10	[1]
Minimum | Diesel	'
Derivative [Line Items]	'
Option contracts settlement date	'2013-10	[1]
Maximum | Unleaded Fuel	'
Derivative [Line Items]	'
Option contracts settlement date	'2015-03	[1]
Maximum | Diesel	'
Derivative [Line Items]	'
Option contracts settlement date	'2015-03	[1]
[1]	The settlement of the put and call option contracts is based upon the New York Mercantile Exchange’s New York Harbor Reformulated Gasoline Blendstock for Oxygen Blending and the U.S. Department of Energy’s weekly retail on-highway diesel fuel price for the month.

Location_and_Amounts_of_Deriva

Location and Amounts of Derivative Fair Values in Condensed Consolidated Balance Sheets (Detail) (Derivatives Not Designated as Hedging Instruments, Commodity contracts, Fuel price derivatives, at fair value, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Fuel price derivatives, at fair value	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivatives Classified as Assets	$488	$0
Derivatives Classified as Liabilities	$983	$1,729

Location_and_Amounts_of_Deriva1

Location and Amounts of Derivative Gains and Losses in Condensed Consolidated Statements of Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Derivatives in Cash Flow Hedging Relationships | Interest rate contracts	'	'	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'		'
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	'	'	$0	[1]	$60	[1]
Derivatives Not Designated as Hedging Instruments | Commodity contracts | Net realized and unrealized gains (losses) on fuel price derivatives	'	'	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'		'
Amount of Gain or (Loss) Recognized in Income on Derivative	-3,640	-14,026	-2,781		-12,046
Financing interest expense | Derivatives in Cash Flow Hedging Relationships	'	'	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'		'
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	'	'	0		-109
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	'	'	$0		$0
[1]	The amount of gain or (loss) recognized in other comprehensive income ("OCI") on the Company’s interest rate swap arrangements has been recorded net of tax impact of $35 in 2012.

Location_and_Amounts_of_Deriva2

Location and Amounts of Derivative Gains and Losses in Condensed Consolidated Statements of Income (Parenthetical) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2012
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Tax impacts on interest rate swap arrangements	$35

Financing_Debt_Additional_Info

Financing Debt - Additional Information (Detail) (USD $)

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

1 Months Ended

9 Months Ended

Sep. 30, 2013

Jan. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jan. 18, 2013

Jan. 18, 2013

23-May-11

Jan. 18, 2013

Jan. 30, 2013

23-May-11

Jan. 18, 2013

Jan. 18, 2013

Sep. 30, 2013

Sep. 30, 2013

Senior Notes

Senior Notes

Semi Annual Payment, First Payment

Semi Annual Payment, Second Payment

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

2013 Credit Agreement

Senior Notes Redeemed Prior to February One Twenty Sixteen

Senior Notes Redeemed Prior to February One Twenty Eighteen

Senior Notes

Senior Notes

Term Loans Facility

Term Loans Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Minimum

Letter of Credit

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit agreement loan, term

'

'

'

'

'

'

'5 years

'

'5 years

'

'

'

'

'

'

Credit agreement loan, maximum

'

'

'

'

'

'

$300,000,000

'

$800,000,000

$700,000,000

'

'

$150,000,000

'

'

Principal remaining outstanding amount

'

'

'

'

'

'

'

'

'

'

'

300,000,000

'

'

'

Credit agreement loan, option to increase

'

'

'

'

'

100,000,000

'

'

'

'

'

'

'

'

'

Credit agreement outstanding amount

'

'

'

'

'

'

'

185,000,000

'

'

700,000,000

'

'

'

'

Debt instrument, aggregate principal amount

'

$400,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, interest rate

'

4.75%

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, issuance price as a percentage of principal amount

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, maturity date

'

'

1-Feb-23

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, interest payable month and day

'

'

'

'--02-01

'--08-01

'

'

'

'

'

'

'

'

'

'

Debt instrument, interest payment commencement date

'

'

1-Aug-13

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, redemption percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

35.00%

'

Debt instrument, redemption price as a percentage of principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

104.75%

100.00%

Debt instrument, redemption date

1-Feb-18

'

'

'

'

'

'

'

'

'

'

'

'

1-Feb-16

'

Debt repurchase price

101.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Notes_Redemption_Prices_for_Fu

Notes Redemption Prices for Future year (Detail)	9 Months Ended
	Sep. 30, 2013
Senior Notes Redeemed During Twelve Months Beginning February 1, 2018	'
Debt Instrument [Line Items]	'
Percentage of Principal Amount of Notes	102.38%
Senior Notes Redeemed During Twelve Months Beginning February 1, 2019	'
Debt Instrument [Line Items]	'
Percentage of Principal Amount of Notes	101.58%
Senior Notes Redeemed During Twelve Months Beginning February 1, 2020	'
Debt Instrument [Line Items]	'
Percentage of Principal Amount of Notes	100.79%
Senior Notes Redeemed During Twelve Months Beginning February 1, 2021	'
Debt Instrument [Line Items]	'
Percentage of Principal Amount of Notes	100.00%

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value and Related Hierarchy Levels (Detail) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	$16,208		$16,350
Executive deferred compensation plan trust	4,048	[1]	2,921	[1]
Total fuel price derivatives - liabilities	'		1,729
Contingent consideration	'		313	[2]
Mortgage-backed securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	867		1,839
Asset-backed securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	1,490		1,654
Municipal bonds	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	535		641
Equity securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	13,316		12,216
Fuel price derivatives - unleaded fuel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - assets	22	[3]	'
Total fuel price derivatives - liabilities	'		1,622	[3]
Fuel price derivatives - diesel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - liabilities	517	[3]	107	[3]
Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	13,316		12,216
Executive deferred compensation plan trust	4,048	[1]	2,921	[1]
Contingent consideration	'		0	[2]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	13,316		12,216
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fuel price derivatives - unleaded fuel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - assets	0	[3]	'
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fuel price derivatives - diesel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - liabilities	0	[3]	'
Significant Other Observable Inputs (Level 2)	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	2,892		4,134
Total fuel price derivatives - liabilities	'		1,622
Contingent consideration	'		0	[2]
Significant Other Observable Inputs (Level 2) | Mortgage-backed securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	867		1,839
Significant Other Observable Inputs (Level 2) | Asset-backed securities	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	1,490		1,654
Significant Other Observable Inputs (Level 2) | Municipal bonds	'		'
Fair Value Measurements [Line Items]	'		'
Total available-for-sale securities	535		641
Significant Other Observable Inputs (Level 2) | Fuel price derivatives - unleaded fuel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - assets	22	[3]	'
Total fuel price derivatives - liabilities	'		1,622	[3]
Significant Other Observable Inputs (Level 2) | Fuel price derivatives - diesel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - liabilities	0	[3]	'
Significant Other Observable Inputs (Level 3)	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - liabilities	'		107
Contingent consideration	'		313	[2]
Significant Other Observable Inputs (Level 3) | Fuel price derivatives - unleaded fuel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - assets	0	[3]	'
Significant Other Observable Inputs (Level 3) | Fuel price derivatives - diesel	'		'
Fair Value Measurements [Line Items]	'		'
Total fuel price derivatives - liabilities	$517	[3]	$107	[3]
[1]	The fair value of these instruments is recorded in other assets.
[2]	The fair value of the contingent consideration is recorded in accrued expenses.
[3]	The balance sheet presentation combines unleaded fuel and diesel fuel positions.

Fair_Value_Additional_Informat

Fair Value - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012		Jun. 30, 2013	Mar. 31, 2012
In Thousands, unless otherwise specified				UNIK	Rapid! Financial Services LLC
Fair Value Measurements [Line Items]	'	'		'	'
Notes outstanding, carrying value	$400,000	$0		'	'
Notes outstanding, fair value	360,000	'		'	'
Amount of increase in the value of a contingent consideration liability	'	'		201	'
Contingent consideration	'	$313	[1]	$511	$8,486
[1]	The fair value of the contingent consideration is recorded in accrued expenses.

Reconciliation_of_Beginning_an

Reconciliation of Beginning and Ending Balances for Assets (Liabilities) Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level Three) (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Contingent Consideration	'		'		'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'		'		'		'
Beginning balance	'		$0		($313)		($9,325)
Included in earnings (a)	'		'		-198	[1]	839	[1]
Included in other comprehensive income	'		'		0		0
Purchases, issuances and settlements	'		-991		'		-991
Transfers (in)/out of Level 3	'		'		511		8,486
Ending balance	0		-991		0		-991
Fuel price derivatives - diesel	'		'		'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'		'		'		'
Beginning balance	498		3,398		-107		-25
Included in earnings (a)	-1,015	[2]	-3,812	[2]	-410	[1]	-389	[1]
Included in other comprehensive income	0		0		0		0
Ending balance	($517)		($414)		($517)		($414)
[1]	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the nine months ended September 30, 2013 and 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.
[2]	Gains and losses (realized and unrealized), associated with fuel price derivatives, included in earnings for the three months ended September 30, 2013 and 2012, are reported in net realized and unrealized losses on fuel price derivatives on the unaudited condensed consolidated statements of income. Gains associated with contingent consideration, included in earnings for the three months ended September 30, 2012, are reported in other expenses and loss of foreign currency transactions on the unaudited condensed consolidated statements of income.

Quantitative_Information_About

Quantitative Information About Level Three Fair Value Measurements (Detail) (Fuel price derivatives - diesel, USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified							Option Model	Option Model
							Minimum	Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]	'	'	'	'	'	'	'	'
Fair value	($517)	$498	($107)	($414)	$3,398	($25)	'	'
Future retail price of diesel (in dollars per gallon)	'	'	'	'	'	'	3.71	3.94

Reconciliation_of_Comprehensiv

Reconciliation of Comprehensive Income (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified			Unrealized Gains and Losses on Available- for-Sale Securities	Unrealized Gains and Losses on Available- for-Sale Securities	Unrealized Gains and Losses on Available- for-Sale Securities	Unrealized Gains and Losses on Available- for-Sale Securities	Foreign Currency Items	Foreign Currency Items	Foreign Currency Items	Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'	'	'	'	'	'	'
Beginning balance	$337	$37,379	($222)	$270	$197	$200	($7,052)	$28,631	$37,182	$30,448
Other comprehensive (loss) income	'	'	-73	44	-492	114	7,684	9,006	-36,550	7,189
Ending balance	$337	$37,379	($295)	$314	($295)	$314	$632	$37,637	$632	$37,637

Recovered_Sheet1

Redeemable Noncontrolling Interest - Additional Information (Detail) (UNIK)	Aug. 30, 2012
UNIK	'
Redeemable Noncontrolling Interest [Line Items]	'
Percent of ownership interest acquired	51.00%

Recovered_Sheet2

Redeemable Noncontrolling Interests (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reconciliation of Redeemable Noncontrolling Interest [Roll Forward]	'	'	'	'
Balance, beginning of period	$19,650	$0	$21,662	$0
Acquisition of subsidiary at fair value	'	21,904	'	21,904
Net loss attributable to noncontrolling interest	-60	-14	-333	-14
Currency translation adjustment	172	223	-1,567	223
Ending balance	$19,762	$22,113	$19,762	$22,113

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Total stock-based compensation cost recognized	$6,882
Total unrecognized compensation cost	$10,606

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'	'	'
Income tax expense	'	'	'	$31,083	'
Write-off of refund claim payable to former shareholder of RD Card Holding	0	0	0	9,750	'
Undistributed earnings of certain foreign subsidiaries	$2,507	'	$2,507	'	$1,756

Segment_Information_Additional

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2013
	Segment
Segment Reporting [Abstract]	'
Number of reportable segments	2

Reportable_Segment_Results_Det

Reportable Segment Results (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Disclosure [Line Items]	'	'	'	'
Total Revenues	$191,525	$160,967	$535,180	$454,153
Depreciation and Amortization	'	'	45,021	35,604
Provision for Income Taxes	26,224	20,845	68,097	94,780
Adjusted Net Income	50,422	42,035	129,790	116,681
Operating Segments	'	'	'	'
Segment Reporting Disclosure [Line Items]	'	'	'	'
Total Revenues	191,525	160,967	535,180	454,153
Operating Interest Expense	976	1,242	3,205	3,429
Depreciation and Amortization	6,109	6,297	18,704	18,940
Provision for Income Taxes	29,303	27,463	75,602	69,634
Adjusted Net Income	50,422	42,035	129,790	116,681
Operating Segments | Fleet payment solutions	'	'	'	'
Segment Reporting Disclosure [Line Items]	'	'	'	'
Total Revenues	136,874	117,877	393,953	341,709
Operating Interest Expense	427	838	1,392	2,685
Depreciation and Amortization	5,767	5,856	17,358	17,699
Provision for Income Taxes	21,726	21,874	58,474	56,027
Adjusted Net Income	35,119	33,641	99,950	94,169
Operating Segments | Other payment solutions	'	'	'	'
Segment Reporting Disclosure [Line Items]	'	'	'	'
Total Revenues	54,651	43,090	141,227	112,444
Operating Interest Expense	549	404	1,813	744
Depreciation and Amortization	342	441	1,346	1,241
Provision for Income Taxes	7,577	5,589	17,128	13,607
Adjusted Net Income	$15,303	$8,394	$29,840	$22,512

Reconciliation_of_Adjusted_Net

Reconciliation of Adjusted Net Income to Net Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting [Abstract]	'	'	'	'
Adjusted net income WEX Inc.	$50,422	$42,035	$129,790	$116,681
Unrealized (loss) gains on fuel price derivatives	-2,733	-12,849	1,234	-1,841
Amortization of acquired intangible assets	-8,051	-5,411	-24,564	-15,481
Goodwill impairment	0	-16,171	0	-16,171
Deferred loan costs associated with the extinguishment of debt	0	0	-1,004	0
Non-cash adjustments related to tax receivable agreement	150	0	150	0
Change in tax refund due to former shareholders of RD Card Holding Australia	0	0	0	9,750
Other adjustments related to Fleet One acquisition	658	0	658	0
ANI adjustments attributable to noncontrolling interest	313	77	971	77
Tax impact	3,079	6,617	7,505	-25,146
Net earnings attributable to WEX Inc.	$43,838	$14,298	$114,740	$67,869