WEX (WEX) 10-Q 10 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	WEX Inc.
Trading Symbol	WEX
Entity Central Index Key	0001309108
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		43,249,922

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Payment processing revenue	$ 266,312	$ 239,715
Account servicing revenue	87,086	78,704
Finance fee revenue	46,373	48,881
Other revenue	61,619	57,989
Total revenues	381,876	354,028
Cost of services
Service fees	14,246	12,326
Provision for credit losses	17,791	14,226
Operating interest	9,564	8,485
Depreciation and amortization	20,513	20,450
Total cost of services	153,233	128,593
General and administrative	64,405	55,309
Sales and marketing	64,119	56,541
Depreciation and amortization	31,184	29,726
Operating income	68,935	83,859
Financing interest expense	(31,112)	(27,337)
Net foreign currency (loss) gain	(3,885)	390
Net unrealized (loss) gain on financial instruments	(11,912)	13,508
Income before income taxes	22,026	70,420
Income taxes	5,818	17,749
Net income	16,208	52,671
Less: Net income from non-controlling interests	74	701
Net income attributable to shareholders	$ 16,134	$ 51,970
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)	$ 0.37	$ 1.21
Diluted (in dollars per share)	$ 0.37	$ 1.20
Weighted average common shares outstanding:
Basic (in shares)	43,220	43,049
Diluted (in shares)	43,572	43,450
Payment processing revenue
Revenues
Payment processing revenue	$ 186,798	$ 168,454
Cost of services
Processing costs	$ 91,119	$ 73,106

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 16,208	$ 52,671
Foreign currency translation	4,371	1,693
Comprehensive income	20,579	54,364
Less: Comprehensive income attributable to non-controlling interests	36	991
Comprehensive income attributable to WEX Inc.	$ 20,543	$ 53,373

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 387,274	$ 541,498
Restricted cash	138,804	13,533
Accounts receivable (net of allowances of $46,742 in 2019 and $46,948 in 2018)	2,830,555	2,584,203
Securitized accounts receivable, restricted	135,438	109,871
Prepaid expenses and other current assets	153,093	149,021
Total current assets	3,645,164	3,398,126
Property, equipment and capitalized software (net of accumulated depreciation of $325,067 in 2019 and $307,750 in 2018)	196,977	187,868
Goodwill	2,331,110	1,832,129
Other intangible assets (net of accumulated amortization of $542,833 in 2019 and $509,055 in 2018)	1,382,279	1,034,194
Investment securities	24,772	24,406
Deferred income taxes, net	11,091	9,643
Other assets	363,849	284,229
Total assets	7,955,242	6,770,595
Liabilities and Stockholders’ Equity
Accounts payable	1,093,128	814,742
Accrued expenses	278,413	312,268
Restricted cash payable	138,804	13,533
Short-term deposits	835,338	927,444
Short-term debt, net	184,357	216,517
Other current liabilities	86,388	27,067
Total current liabilities	2,616,428	2,311,571
Long-term debt, net	2,809,361	2,133,923
Long-term deposits	300,349	345,231
Deferred income taxes, net	203,274	151,685
Other liabilities	108,949	32,261
Total liabilities	6,038,361	4,974,671
Redeemable non-controlling interest	99,993	0
Stockholders’ Equity
Common stock $0.01 par value; 175,000 shares authorized; 47,674 issued in 2019 and 47,557 in 2018; 43,246 shares outstanding in 2019 and 43,129 in 2018	476	475
Additional paid-in capital	635,046	593,262
Retained earnings	1,456,327	1,481,593
Accumulated other comprehensive loss	(112,882)	(117,291)
Treasury stock at cost; 4,428 shares in 2019 and 2018	(172,342)	(172,342)
Total WEX Inc. stockholders’ equity	1,806,625	1,785,697
Non-controlling interest	10,263	10,227
Total stockholders’ equity	1,816,888	1,795,924
Total liabilities and stockholders’ equity	$ 7,955,242	$ 6,770,595

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, reserve for credit losses	$ 46,742	$ 46,948
Property, equipment and capitalized software, accumulated depreciation	325,067	307,750
Accumulated amortization	$ 542,833	$ 509,055
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	175,000,000	175,000,000
Common stock, shares issued (in shares)	47,674,000	47,557,000
Common stock, shares outstanding (in shares)	43,246,000	43,129,000
Treasury stock, shares (in shares)	4,428,000	4,428,000

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Issued	Additional Paid–In Capital	Accumulated Other Comprehensive Loss	Treasury Stock	Retained Earnings	Non–Controlling Interest
Beginning Balance (in shares) at Dec. 31, 2017		47,352
Beginning balance at Dec. 31, 2017	$ 1,630,100	$ 473	$ 569,319	$ (89,230)	$ (172,342)	$ 1,312,660	$ 9,220
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued (in shares)		148
Stock issued	576	$ 2	574
Share repurchases for tax withholdings	(11,810)		(11,810)
Stock-based compensation expense	8,955		8,955
Foreign currency translation	1,693			1,403			290
Net income	52,671					51,970	701
Ending Balance (in shares) at Mar. 31, 2018		47,500
Ending balance at Mar. 31, 2018	1,682,823	$ 475	567,038	(87,827)	(172,342)	1,365,268	10,211
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balances, adjusted	1,795,924	$ 475	593,262	(117,291)	(172,342)	1,481,593	10,227
Beginning Balance (in shares) at Dec. 31, 2018		47,557
Beginning balance at Dec. 31, 2018	1,795,924
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued (in shares)		117
Stock issued	405	$ 1	404
Share repurchases for tax withholdings	(9,723)		(9,723)
Stock-based compensation expense	9,703		9,703
Adjustments of redeemable non-controlling interest	(41,400)		41,400			(41,400)
Foreign currency translation	4,371			4,409			(38)
Net income	16,208					16,134	74
Ending Balance (in shares) at Mar. 31, 2019		47,674
Ending balance at Mar. 31, 2019	$ 1,816,888	$ 476	$ 635,046	$ (112,882)	$ (172,342)	$ 1,456,327	$ 10,263

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net income	$ 16,208	$ 52,671
Adjustments to reconcile net income to net cash provided by (used for) operating activities:
Net unrealized loss (gain)	12,870	(12,780)
Stock-based compensation	9,703	8,955
Depreciation and amortization	51,697	50,176
Debt restructuring and debt issuance cost amortization	2,095	3,676
Provision for deferred taxes	3,402	16,296
Provision for credit losses	17,791	14,226
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable and securitized accounts receivable	(239,658)	(264,475)
Prepaid expenses and other current and other long-term assets	(7,109)	121,622
Accounts payable	245,657	119,334
Accrued expenses and restricted cash payable	(43,554)	(17,404)
Income taxes	(1,153)	(1,339)
Other current and other long-term liabilities	2,161	(3,152)
Net cash provided by operating activities	70,110	87,806
Cash flows from investing activities
Purchases of property, equipment and capitalized software	(28,385)	(14,770)
Acquisitions, net of cash acquired	(568,426)	0
Purchase of equity investment	0	(2,307)
Purchases of investment securities	(140)	(121)
Maturities of investment securities	85	72
Net cash used for investing activities	(596,866)	(17,126)
Cash flows from financing activities
Repurchase of share-based awards to satisfy tax withholdings	(9,723)	(11,810)
Proceeds from stock option exercises	405	576
Net change in deposits	(136,717)	(185,433)
Net activity on other debt	(57,556)	(19,027)
Borrowings on revolving credit facility	863,756	488,503
Repayments on revolving credit facility	(693,600)	(625,821)
Borrowings on term loans	550,000	153,000
Repayments on term loans	(15,871)	(9,076)
Debt issuance costs	(3,443)	(2,907)
Net change in securitized debt	(1,191)	19,402
Net cash provided by (used for) financing activities	496,060	(192,593)
Effect of exchange rates on cash, cash equivalents and restricted cash	1,743	(587)
Net change in cash, cash equivalents and restricted cash	(28,953)	(122,500)
Cash, cash equivalents and restricted cash, beginning of period	555,031	522,385
Cash, cash equivalents and restricted cash, end of period	526,078	399,885
Supplemental disclosure of non-cash investing and financing activities
Capital expenditures incurred but not paid	$ 2,046	$ 4,801

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	1. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10–Q and Rule 10–01 of Regulation S–X. Accordingly, they do not include all information and notes required by GAAP for complete financial statements. 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, 2018 , filed with the SEC on March 18, 2019 and our Form 10–K/A filed with the SEC on March 20, 2019. 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 months ended March 31, 2019 are not necessarily indicative of the results for any future periods or the year ending December 31, 2019 . Effective January 1, 2019, the Company modified the presentation of the unaudited condensed balance sheets to separately classify its restricted cash payable. The prior period has been reclassified to conform with this presentation. There was no change to current liabilities as a result of this change. We apply the same accounting policies in preparing our quarterly and annual financial statements, with the exception of the new leasing standard which is required to be adopted on a prospective basis. Refer to Note 2, Recent Accounting Pronouncements, for more information. The Company rounds amounts in the unaudited condensed consolidated financial statements to thousands and calculates all per-share data from underlying whole-dollar amounts. Thus, certain amounts may not foot, crossfoot or recalculate based on reported numbers due to rounding. Revision of Prior Period Unaudited Condensed Consolidated Financial Statements for Correction of Immaterial Errors As more fully described in our 2018 Form 10–K, in 2018 we revised our prior year financial statements to correct for immaterial errors in the financial statements of our Brazilian subsidiary and certain other immaterial errors impacting prior years that were not previously recorded. The accompanying quarterly financial statements have been revised for these errors. Collectively, hereinafter these revisions to correct are referred to as the “Revised” financial statements or the “Revision”. Management believes that the effects of this Revision are not material to our previously issued unaudited condensed consolidated financial statements. The effects of the Revision on our unaudited condensed consolidated statements of income and cash flows were as follows: Three months ended March 31, 2018 (In thousands, except per share data) As Previously Reported Brazil Adjustments Other Immaterial Adjustments As Revised Total revenues $ 354,829 $ (801 ) $ — $ 354,028 Processing costs $ 79,640 $ (6,534 ) $ — $ 73,106 Provision for credit losses $ 13,990 $ 236 $ — $ 14,226 Operating income $ 78,362 $ 5,497 $ — $ 83,859 Income taxes $ 15,589 $ 2,343 $ (183 ) $ 17,749 Net income $ 49,334 $ 3,154 $ 183 $ 52,671 Net income attributable to shareholders $ 48,633 $ 3,154 $ 183 $ 51,970 Net income attributable to WEX Inc. per share Basic $ 1.13 $ 0.08 $ — $ 1.21 Diluted $ 1.12 $ 0.08 $ — $ 1.20 Three months ended March 31, 2018 (In thousands) As Previously Reported Brazil Adjustments Other Immaterial Adjustments As Revised Net cash provided by operating activities $ 85,243 $ — $ 2,563 $ 87,806 Effect of exchange rates on cash, cash equivalents and restricted cash $ (2,577 ) $ — $ 1,990 $ (587 ) Cash, cash equivalents and restricted cash, beginning of period $ 526,938 $ — $ (4,553 ) $ 522,385

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	2. Recent Accounting Pronouncements The following table provides a brief description of accounting pronouncements adopted during the three months ended March 31, 2019 and recent accounting pronouncements that could have a material effect on our financial statements: Standard Description Date/Method of Adoption Effect on financial statements or other significant matters Adopted During the Three Months Ended March 31, 2019 ASU 2016–02 This standard requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The Company adopted ASU 2016–02 effective January 1, 2019, using the modified retrospective approach, and all practical expedients permitted under the transition guidance. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016–02, Leases (Topic 842), which requires leases with a duration greater than twelve months to be recognized on the balance sheet as right-of-use (“ROU”) assets and lease liabilities. We adopted the new standard using the modified retrospective approach and have elected the package of practical expedients permitted under the transition guidance, including the hindsight practical expedients for expired or existing contracts, which allowed us to carryforward our historical determination of (i) whether a contract is or contains a lease, (ii) lease classification and (iii) initial direct costs. Additionally, we elected the practical expedients which allowed us to (i) not perform an allocation of lease and non-lease components for real estate leases, (ii) continue to account for short-term leases under Topic 840 and (iii) utilize our incremental borrowing rate (“IBR”), rather than the rate implicit in each lease, to calculate the present value of the remaining lease payments. As such, the unaudited condensed consolidated financial statements for the period ended March 31, 2019 are presented under the new standard, while comparative periods presented continue to be reported in accordance with Topic 840. The most significant impact of adoption was the recording of operating lease ROU assets and operating lease liabilities on our unaudited condensed consolidated balance sheets at January 1, 2019. Refer to Note 14, Leases, for more information. The standard did not materially impact our results of operations or cash flows. ASU 2018 – 15 This standard clarifies the accounting for capitalizing implementation costs in a cloud computing arrangement that is a service contract. The standard provides that implementation costs be treated using the same criteria used for internal-use software development costs, with amortization expense being recorded in the same income statement expense line as the hosted service costs and over the expected term of the hosting arrangement. Effective January 1, 2019, the Company early adopted ASU 2018–15 on a prospective basis. Under the standard, we now capitalize implementation costs related to our cloud migration of technology platforms to the cloud. Such amounts are amortized over the lesser of the term of the hosting arrangement, considering any explicit renewal options for which we are reasonably certain to exercise, or the useful life of the underlying hosted software. We do not expect that adoption of this standard will have a material impact on our results of operations, cash flows or consolidated financial position. Not Yet Adopted as of March 31, 2019 ASU 2016 – 13 This standard requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses will be based on historical experience, current conditions and reasonable and supportable forecasts that impact the collectability of the reported amount. The standard is effective January 1, 2020. The Company is evaluating the impact the standard will have on its consolidated financial statements and related disclosures.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	3. Revenue In accordance with Topic 606, revenue is recognized when, or as, performance obligations are satisfied as defined by the terms of the contract, in an amount that reflects the consideration to which the Company expects to be entitled in exchange for goods or services provided. The vast majority of the Company’s Topic 606 revenue is derived from stand-ready commitments to provide payment processing, transaction processing and SaaS services and support. Revenue is recognized based on the value of services transferred to date using a time elapsed output method. For payment processing and transaction processing, services are considered to be transferred when a transaction is captured and the Company has validated that the transaction has no errors. Point-in-time revenue recognized during the three months ended March 31, 2019 and 2018 was not material. Topic 606 does not apply to rights or obligations associated with financial instruments, including the Company’s finance fee and interest income from banking relationships and cardholders, certain other fees associated with cardholder arrangements and commissions paid related to such agreements, which continue to be within the scope of Topic 310, Receivables . In addition, gains on sale of WEX Latin America receivables are included in other revenue and are within the scope of ASC 860, Transfers and Servicing . We disaggregate our revenue from contracts with customers by service-type for each of our segments, as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. See Note 18, Segment Information, for further information. The following table disaggregates our consolidated revenue for the three months ended March 31, 2019 : Three Months Ended March 31, 2019 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Topic 606 revenues Payment processing revenue $ 107,408 $ 59,998 $ 19,392 $ 186,798 Account servicing revenue 6,800 10,585 37,262 54,647 Other revenue 16,986 1,105 6,776 24,867 Total Topic 606 revenues $ 131,194 $ 71,688 $ 63,430 $ 266,312 Non-Topic 606 revenues Account servicing revenue $ 32,439 $ — $ — $ 32,439 Finance fee revenue 45,864 357 152 46,373 Other revenue 23,285 9,603 3,864 36,752 Total non-Topic 606 revenues $ 101,588 $ 9,960 $ 4,016 $ 115,564 Total revenues $ 232,782 $ 81,648 $ 67,446 $ 381,876 The following table disaggregates our consolidated revenue for the three months ended March 31, 2018 : Three Months Ended March 31, 2018 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Topic 606 revenues Payment processing revenue $ 106,978 $ 44,777 $ 16,699 $ 168,454 Account servicing revenue 8,466 9,469 27,025 44,960 Other revenue 17,042 1,117 8,142 26,301 Total Topic 606 revenues $ 132,486 $ 55,363 $ 51,866 $ 239,715 Non-Topic 606 revenues Account servicing revenue $ 33,744 — — $ 33,744 Finance fee revenue 43,604 259 5,018 48,881 Other revenue 20,531 11,157 — 31,688 Total non-Topic 606 revenues $ 97,879 $ 11,416 $ 5,018 $ 114,313 Total revenues $ 230,365 $ 66,779 $ 56,884 $ 354,028 Payment Processing Revenue Payment processing revenue consists primarily of interchange income. Interchange income is a fee paid by a merchant bank (“merchant”) to the card-issuing bank (generally the Company) in exchange for the Company facilitating and processing transactions with cardholders. Interchange fees are set by the card network. WEX processes transactions through both closed-loop and open-loop networks. • Our Fleet Solutions segment interchange income primarily relates to revenue earned on transactions processed through the Company’s proprietary closed-loop fuel networks. In closed-loop fuel network arrangements, written contracts are entered into between the Company and merchants, which determine the interchange fee charged on transactions. The Company extends short-term credit to the fleet cardholder and pays the merchant the purchase price for the cardholder’s transaction, less the interchange fees the Company retains. The Company collects the total purchase price from the fleet cardholder. In Europe, interchange income is specifically derived from the difference between the negotiated price of fuel from the supplier and the agreed upon price paid by fleet cardholders. • Interchange income in our Travel and Corporate Solutions and Health and Employee Benefit Solutions segments relates to revenue earned on transactions processed through open-loop networks. In open-loop network arrangements, there are several intermediaries involved between the merchant and the cardholder, and written contracts do not exist between all parties involved in the process. Rather, the transaction is governed by the rates determined by the payment network at the point-of-sale. This framework dictates the interchange rate, the risk of loss, dispute procedures and timing of payment. For these transactions, there is an implied contract between the Company and the merchant. In our Travel and Corporate Solutions segment, the Company remits payment to the card network for the purchase price of the cardholder transaction, less the interchange fees the Company earns. The Company collects the total purchase price from the cardholder. In our Health and Employee Benefit Solutions segment, funding of transactions and collections from cardholders is performed by third-party sponsor banks, who remit a portion of the interchange fee to us. The Company has determined that the merchant is the customer as it relates to interchange income regardless of the type of network through which transactions are processed. The Company’s primary performance obligation to merchants is a stand-ready commitment to provide payment and transaction processing services as the merchant requires, which is satisfied over time in daily increments. Since the timing and quantity of transactions to be processed by us is not determinable, the total consideration is determined to be variable consideration. The variable consideration for our payment and transaction processing service is usage-based and therefore specifically relates to our efforts to satisfy our obligation. The variability is satisfied each day the service is provided to the customer. We directly ascribe variable fees to the distinct day of service to which it relates, and we consider the services performed each day in order to ascribe the appropriate amount of total fees to that day. Therefore, we measure interchange income on a daily basis based on the services that are performed on that day. The Company determined that WEX does not control the services performed by merchant acquirers, card networks, sponsor banks and online bill payment aggregators as each of these parties is the primary obligor for their portion of payment and transaction processing services performed. Therefore, interchange income is recognized net of any fees owed to these intermediaries. The Company determined that services performed by third-party payment processors are controlled by WEX as the Company is responsible for directing how the third-party payment processor authorizes and processes transactions on the Company’s behalf. Therefore, such fees paid to third-party payment processors are recorded as service fees within cost of services. Additionally, the Company enters into contracts with certain large customers or strategic cardholders that provide for fee rebates tied to performance milestones. If such fee rebates constitute consideration payable to a customer or to another party that purchases services from the customer, they are considered variable consideration and are recorded as a reduction in payment processing revenue in the same period that the related interchange income is recognized. For the three months ended March 31, 2019 and 2018 , such variable consideration totaled $198.7 million and $198.5 million , respectively. Certain other fee rebates that constitute costs to obtain a contract are recorded as sales and marketing expenses. Account Servicing Revenue In our Fleet Solutions segment, account servicing revenue is primarily comprised of monthly fees charged to cardholders based on the number of vehicles serviced. These fees are primarily in return for providing monthly vehicle data reports and are recognized on a monthly basis as the service is provided. Additionally, account servicing revenue includes other fees recognized as revenue when assessed to the cardholder as part of the lending relationship, which is outside the scope of Topic 606. The Company also recognizes account servicing revenue related to reporting services on telematics hardware placements and permit sales to our over-the-road fleet customer base, both of which are within the scope of Topic 606. In our Travel and Corporate Solutions segment, account servicing primarily consists of licensing fees for the use of our accounts receivable and accounts payable SaaS platforms. In our Health and Employee Benefit Solutions segment, we recognize account servicing fees for the per-participant per-month fee charged on our SaaS healthcare technology platform. Customers including health plans, third-party administrators, financial institutions and payroll companies typically enter into three to five year contracts, which contain significant termination penalties. Our Travel and Corporate Solutions and Health and Employee Benefit Solutions segments provide SaaS services and support, which are stand-ready commitments and are satisfied over time in a series of daily increments. Revenue is recognized based on an output method using days elapsed to measure progress as the Company transfers control evenly over each monthly subscription period. Finance Fee Revenue The Company earns revenue on overdue accounts, which is recognized as revenue at the time the fees are assessed. The finance fee is calculated using the greater of a minimum charge or a stated late fee rate multiplied by the outstanding balance that is subject to a late fee charge. On occasion, these fees are waived to maintain customer goodwill. The established reserve for such waived amounts is estimated and offset against the late fee revenue recognized. These waived fees amounted to $4.5 million and $4.4 million during the three months ended March 31, 2019 and 2018 , respectively. Finance fee revenue includes amounts earned by the Company’s factoring business, which purchases accounts receivable from third parties at a discount. Through June 2018, the Company also recognized finance fee revenue earned on the Company’s foreign salary advance product. Subsequently, the Company revised its WEX Latin America securitized debt agreement and recognizes gains on the sale of these receivables within “Other revenue” below. See Note 10, Off-Balance Sheet Arrangements, for further information on our WEX Latin America securitization. Other Revenue Other revenue includes transaction processing revenue, professional services including software development projects and other services sold subsequent to the core offerings, and the sales of telematics hardware, all of which are within the scope of Topic 606. Revenue is recognized when control of the services or hardware is transferred to our customers, in an amount that reflects the consideration that we expect to receive in exchange for those services. In addition, international settlement fees and certain other cardholder fees (e.g. replacement card fees) and gains on sale of WEX Latin America receivables are included in other revenue. This revenue is outside the scope of Topic 606 and is recognized upon completion of the related service or the sale date of the receivables. Contract Balances The Company’s contract assets consist of upfront payments made to customers under long-term contracts and are recorded upon payment or when due. The resulting asset is amortized against revenue as the Company performs its obligations under these arrangements. The Company’s contract liabilities consist of customer payments received before the Company has satisfied the associated performance obligations and upfront payments due to the customer. The following table provides information about these contract balances. (In thousands) Contract balance Location on the unaudited condensed consolidated balance sheets March 31, 2019 December 31, 2018 Receivables 1 Accounts receivable, net $ 41,092 $ 32,949 Contract assets Prepaid expenses and other current assets $ 5,576 $ 3,819 Contract assets Other assets $ 20,280 $ 19,232 Contract liabilities Other current liabilities $ 6,594 $ 7,612 1 The majority of the Company’s receivables, which are excluded from the table above, are either due from cardholders, who have not been deemed our customer as it relates to interchange income, or from revenues earned outside of the scope of Topic 606. In the three months ended March 31, 2019 , we recognized revenue of $2.8 million related to contract liabilities at December 31, 2018. In the three months ended March 31, 2018 , revenue recognized related to contract liabilities at January 1, 2018 was immaterial. Remaining Performance Obligations The Company’s unsatisfied, or partially unsatisfied performance obligations as of March 31, 2019 represent the remaining minimum monthly fees on a portion of contracts across the lines of business and contractually obligated professional services yet to be provided by the Company. It is not indicative of the Company’s future revenue, as it relates to an insignificant portion of the Company’s operations. The following table includes revenue expected to be recognized related to remaining performance obligations at the end of the reporting period. (In thousands) Remaining 2019 2020 2021 2022 2023 2024 Total Minimum monthly fees 1 $ 45,776 $ 40,285 $ 23,227 $ 12,313 $ 3,753 $ 639 $ 125,993 Professional services 2 11,655 515 — — — — 12,170 Total remaining performance obligations $ 57,431 $ 40,800 $ 23,227 $ 12,313 $ 3,753 $ 639 $ 138,163 1 The transaction price allocated to the remaining performance obligations represents the minimum monthly fees on certain service contracts, which contain substantive termination penalties that require the counterparty to pay the Company for the aggregate remaining minimum monthly fees upon an early termination for convenience. 2 Includes software development projects and other services sold subsequent to the core offerings, to which the customer is contractually obligated.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions	Asset Acquisition In December 2016, the Company entered into a contract with Chevron to issue and operate branded commercial fleet cards commencing in 2018. During October 2018, the Company entered into a definitive asset purchase agreement to acquire Chevron’s existing trade accounts receivable and customer portfolio from a third party for approximately $223.4 million , of which a portion will be paid during 2019. During 2018, the consideration paid consisted of approximately $162.8 million to acquire the customer portfolio, with $38.9 million paid into escrow for the carrying value of a portion of the accounts receivable at the date of purchase. As of March 31, 2019 , the deposits for the customer portfolio and accounts receivable are recorded in other assets and prepaid expenses and other current assets on the unaudited condensed consolidated balance sheets, respectively. During the second quarter of 2019, when the Company obtains control of the customer portfolio and the customer accounts are converted onto the Company’s payment processing platform, the amounts will be reclassified to other intangible assets and accounts receivable, respectively. We will account for this transaction under the asset acquisition method of accounting. Concurrently with entering into the asset purchase agreement, we modified a number of contract terms, including extending the term of Chevron’s agreement, which is the period that we will use to amortize the other intangible asset on a straight-line basis. Transaction costs related to the acquisition were insignificant and expensed as incurred. Business Acquisitions In both the three months ended March 31, 2019 and 2018, the acquisition and merger related costs related to completed business combinations were immaterial. Discovery Benefits, Inc. On March 5, 2019, the Company acquired Discovery Benefits, an employee benefits administrator, for a total purchase price of $525.6 million , including $50 million which is payable in January 2020. The acquisition was primarily funded with cash on hand and through borrowings under the 2016 Credit Agreement. The seller of Discovery Benefits obtained a 4.9 percent equity interest in the U.S. Health business. The fair value of the equity interest was determined to be $100.0 million on the acquisition date. See Note 12, Redeemable Non-Controlling Interest, for further information. This acquisition has been accounted for as a business combination, with preliminary goodwill reflecting the comprehensive suite of products and services for our partners and customers and opening go-to-market channels to include consulting firms and brokers in our Health and Employee Benefit Solutions segment. The majority of the goodwill associated with this acquisition is deductible for tax purposes. The following is a summary of the preliminary allocation of the purchase price to the assets and liabilities acquired, based on the estimated fair value at the date of acquisition: (In thousands) Cash consideration, net of cash and restricted cash acquired of $125,865 $ 249,781 Fair value of redeemable non-controlling interest 100,000 Deferred cash consideration 50,000 Total consideration, net of cash and restricted cash acquired $ 399,781 Less: Accounts receivable 10,367 Property and equipment 4,904 Customer relationships (a)(d) 213,600 Developed technologies (b)(d) 38,900 Trademarks and trade names (c)(d) 13,800 Other assets 13,589 Accounts payable (3,024 ) Accrued expenses (7,399 ) Restricted cash payable (125,346 ) Deferred income taxes (22,200 ) Other liabilities (10,015 ) Recorded goodwill $ 272,605 (a) Weighted average life - 7.3 years . (b) Weighted average life - 5.4 years . (c) Weighted average life - 7.3 years . (d) The weighted average life of all amortizable intangible assets acquired in this business combination is 7.0 years . Since the acquisition date, DBI has contributed $8.6 million in total revenues and $1.1 million income before income taxes to Company operations. Noventis, Inc. On January 24, 2019, the Company acquired Noventis, a long-time customer and electronic payments network focused on optimizing payment delivery for bills and invoices to commercial entities, for $343.1 million , which was primarily funded with cash on hand and through borrowings under the 2016 Credit Agreement. Excluded from the consideration is $5.6 million paid to certain Noventis shareholders who held unvested option awards at the acquisition date. The modification of these awards to accelerate the vesting resulted in the Company recording this expense as general and administrative expense in our unaudited condensed consolidated statement of income. This acquisition, which expands our reach as a corporate payments supplier and provides more channels to billing aggregators and financial institutions in our Travel and Corporate Payment Solutions segment, was accounted for as a business combination, resulting in the recording of goodwill. The goodwill associated with this acquisition is not deductible for tax purposes. The following is a summary of the preliminary allocation of the purchase price to the assets and liabilities acquired, based on the estimated fair value at the date of acquisition: (In thousands) Total consideration, net of cash and restricted cash acquired of $51,538 $ 291,564 Less: Accounts receivable 23,002 Property and equipment 549 Network relationships (a) (c) 100,900 Developed technologies (b) (c) 15,000 Other assets 2,487 Accounts payable (36,794 ) Deferred income tax liabilities (24,121 ) Other liabilities (2,518 ) Recorded goodwill $ 213,059 (a) Weighted average life - 8.3 years . (b) Weighted average life - 2.9 years . (c) The weighted average life of all amortizable intangible assets acquired in this business combination is 7.6 years . Since the acquisition date, Noventis has contributed $9.2 million in total revenues and $1.8 million loss before income taxes to Company operations. Pavestone Capital, LLC On February 14, 2019, the Company acquired Pavestone Capital, a recourse factoring company that provides working capital to businesses, for a purchase price of $28.1 million , subject to net working capital adjustments. This acquisition, which has been accounted for as a business combination, complements our existing factoring business and as a result the purchase price is primarily allocated to goodwill and accounts receivable in amounts of $12.8 million and $14.6 million , respectively. The goodwill associated with this acquisition is deductible for tax purposes. Since the acquisition date, Pavestone Capital revenues and income before income taxes, which are recorded in our Fleet Solutions segment, were not material to Company operations. No pro forma information has been included in these financial statements as the operations of Pavestone Capital for the period that they were not part of the Company are not material to the Company’s revenues, net income and earnings per share. The Company has not finalized the purchase accounting for Discovery Benefits, Noventis or Pavestone and is currently evaluating the tax basis and allocation of the net assets acquired. Additionally, the Company is performing a valuation of intangible assets acquired in the business combinations. The preliminary estimates could change significantly upon completion of these valuations. Pro Forma Supplemental Information The pro forma information below gives effect to the Discovery Benefits and Noventis acquisitions as if they had been completed on January 1, 2018. These pro forma results have been calculated after applying the Company’s accounting policies, adjustments to reflect amortization associated with intangibles acquired and interest expense associated with the incremental borrowings under the 2016 Credit Agreement used to fund the acquisition and related income tax results. The pro forma financial information is presented for comparative purposes only, based on certain estimates and assumptions, which the Company believes to be reasonable but not necessarily indicative of future results of operations or the results that would have been reported if the acquisitions had been completed on January 1, 2018. The following represents unaudited pro forma operational results as if the acquisitions had occurred January 1, 2018: Three Months Ended March 31, 2019 2018 Total revenues $ 400,982 $ 381,826 Net income attributable to shareholders $ 18,810 $ 42,487 Net income attributable to WEX Inc. per share: Basic $ 0.44 $ 0.99 Diluted $ 0.43 $ 0.98 GO Fuel Card On March 26, 2019, the Company entered into an agreement to acquire Go Fuel Card, a European fuel card business, for a total purchase price of €235.0 million (equivalent of $265.5 million on date of agreement). We expect that this acquisition will strengthen our position in the European market and reduce our sensitivity to retail fuel prices. This transaction is expected to close late in the second quarter or early in the third quarter of 2019, subject to regulatory approvals and other customary closing conditions.

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Accounts Receivable	5. Accounts Receivable In general, the Company’s trade receivables provide for payment terms of 30 days or less. Receivables not paid within the terms of the agreement are generally subject to late fees based upon the outstanding receivable balance. The Company extends revolving credit to certain small fleets, which are subject to interest charges based on the revolving balance not paid in full. The Company had approximately $43.0 million and $18.9 million in receivables with revolving credit balances as of March 31, 2019 and December 31, 2018 , respectively. The increase in revolving credit balances during the three months ended March 31, 2019 was due to the onboarding of a significant customer portfolio. Concentration of Credit Risk The receivables portfolio consists of a large group of homogeneous smaller balances across a wide range of industries, which are collectively evaluated for impairment. No one customer receivable balance represented 10 percent or more of the outstanding receivables balance at March 31, 2019 or December 31, 2018 . The following table presents the outstanding balance of trade accounts receivable that are less than 30 and 60 days past due, in each case, as a percentage of total trade accounts receivable: Delinquency Status March 31, 2019 December 31, 2018 29 days or less past due 96 % 95 % 59 days or less past due 98 % 98 % Reserves for Accounts Receivable Receivables are generally written off when they are 150 days past due or upon declaration of bankruptcy of the customer. The reserve for credit losses is primarily calculated by an analytic model that also takes into account other factors, such as the actual charge-offs for the preceding reporting periods, expected charge-offs and recoveries for the subsequent reporting periods, a review of past due accounts receivable balances, changes in payment patterns, known fraudulent activity in the portfolio, as well as leading economic and market indicators. The following table presents changes in the accounts receivable allowances: Three Months Ended March 31, (In thousands) 2019 2018 Balance, beginning of year $ 46,948 $ 33,387 Provision for credit losses 17,791 14,226 Charges to other accounts 1 4,533 4,442 Charge-offs (24,800 ) (19,221 ) Recoveries of amounts previously charged-off 2,215 1,926 Currency translation 55 99 Balance, end of period $ 46,742 $ 34,859 1 The Company earns revenue by assessing monthly finance fees on accounts with overdue balances. These fees are recognized as revenue at the time the fees are assessed. The finance fee is calculated using the greater of a minimum charge or a stated late fee rate multiplied by the outstanding balance that is subject to a late fee charge. On occasion, these fees are waived to maintain relationship goodwill. Charges to other accounts represents the offset against the late fee revenue recognized when the Company establishes a reserve for such waived amounts.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings per Share	6. Earnings per Share Basic earnings per share is computed by dividing net income attributable to shareholders by the weighted average number of shares of common stock and vested deferred stock units (“DSUs”) outstanding during the year. The computation of diluted earnings per share is similar to the computation of basic earnings per share, except that the denominator is increased for the assumed exercise of dilutive options and assumed issuance of unvested performance-based awards for which the performance condition has been met as of the date of determination using the treasury stock method unless the effect is anti-dilutive. The treasury stock method assumes that proceeds, including cash received from the exercise of employee stock options and the average unrecognized compensation expense for unvested share-based compensation awards, would be used to purchase the Company’s common stock at the average market price during the period. The following table summarizes net income attributable to shareholders and reconciles basic and diluted shares outstanding used in the earnings per share computations: Three Months Ended March 31, (In thousands) 2019 2018 Net income attributable to shareholders $ 16,134 $ 51,970 Weighted average common shares outstanding – Basic 43,220 43,049 Dilutive impact of share-based compensation awards 352 401 Weighted average common shares outstanding – Diluted 43,572 43,450 For the three months ended March 31, 2019 and March 31, 2018 , an immaterial number of outstanding share-based compensation awards were excluded from the computation of diluted earnings per share, as the effect of including these awards would be anti-dilutive.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	7. Derivative Instruments The Company is exposed to certain market risks relating to its ongoing business operations. From time to time, the Company enters into derivative instrument arrangements to manage various risks including interest rate risk. As of December 31, 2018 we had four interest rate swap contracts in effect with a notional amount at inception collectively of $1.0 billion , with maturity dates from December 30, 2020 to December 31, 2022, at interest rates between 1.108 percent and 2.212 percent . On March 12, 2019, the Company entered into three additional interest rate swap contracts. The following table presents the notional amounts, fixed interest rates and maturities of the interest rate swap agreements entered into during the three months ended March 31, 2019 : Tranche A Tranche B Tranche C Notional amount at inception (in thousands) $150,000 $100,000 $200,000 Maturity date 3/12/2022 3/12/2022 3/12/2023 Fixed interest rate 2.41750% 2.42500% 2.41325% Collectively, as of March 31, 2019 , these outstanding interest rate swap contracts are intended to fix the future interest payments associated with $1.5 billion of our variable rate borrowings. At March 31, 2019 , we had variable-rate borrowings of $2.4 billion under our 2016 Credit Agreement. The following table presents information on the location and amounts of interest rate swap gains and losses: (In thousands) Three Months Ended March 31, Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income Statement 2019 2018 Interest rate swap agreements – unrealized portion Net unrealized (loss) gain on financial instruments $ (12,209 ) $ 13,508 Interest rate swap agreements – realized portion Financing interest income $ 2,116 $ 313 See Note 11, Fair Value, for more information regarding the valuation of the Company’s interest rate swaps.

Deposits

Deposits	3 Months Ended
	Mar. 31, 2019
Banking and Thrift [Abstract]
Deposits	8. Deposits WEX Bank has issued certificates of deposit with maturities ranging from one year to five years, with interest rates ranging from 1.30 percent to 3.52 percent as of both March 31, 2019 and December 31, 2018. WEX Bank may issue brokered deposits, subject to FDIC rules governing minimum financial ratios, which include risk-based asset and capital requirements. As of March 31, 2019 , all brokered deposits were in denominations of $250 thousand or less, corresponding to FDIC deposit insurance limits. The Company requires deposits from certain customers as collateral for credit that has been extended. These deposits are generally non-interest bearing. Interest-bearing brokered money market deposits are issued at variable rates based on LIBOR or the Federal Funds rate. Money market deposits may be withdrawn by the holder at any time, although notification may be required and the monthly number of transactions is limited. Interest-bearing brokered money market deposits, customer deposits and certificates of deposit with maturities within one year are classified as short-term deposits on our unaudited condensed consolidated balance sheets. WEX Bank is required to maintain reserves against a percentage of certain customer deposits by keeping balances with the Federal Reserve Bank. The required reserve based on the outstanding customer deposits was $11.2 million and $11.1 million at March 31, 2019 and December 31, 2018 , respectively. The following table presents the composition of deposits: (In thousands) March 31, 2019 December 31, 2018 Interest-bearing brokered money market deposits $ 238,940 $ 283,790 Customer deposits 128,402 138,072 Certificates of deposit with maturities within 1 year (a) 467,996 505,582 Short-term deposits 835,338 927,444 Certificates of deposit with maturities greater than 1 year and less than 5 years (a) 300,349 345,231 Total deposits $ 1,135,687 $ 1,272,675 Weighted average cost of funds on certificates of deposit outstanding 2.40 % 2.36 % Weighted average cost of interest-bearing brokered money market deposits 2.55 % 2.49 % (a) Certificates of deposit are classified as short-term or long-term within our unaudited condensed consolidated balance sheets based on maturity date. Sources of Funds ICS Purchases WEX Bank participates in the ICS service offered by Promontory Interfinancial Network, which allows WEX Bank to purchase brokered money market demand accounts and demand deposit accounts in an amount not to exceed $125.0 million as part of a one-way buy program. There were no outstanding balances for ICS purchases at March 31, 2019 and December 31, 2018.

Financing and Other Debt

Financing and Other Debt	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Financing and Other Debt	9. Financing and Other Debt The following table summarizes the Company’s total outstanding debt: (In thousands) March 31, 2019 December 31, 2018 Revolving line-of-credit facility under 2016 Credit Agreement (a) $ 169,206 $ — Term loans under 2016 Credit Agreement (a) 2,279,213 1,745,084 Notes outstanding (a) 400,000 400,000 Securitized debt 105,932 106,872 Participation debt 55,677 114,849 Borrowed federal funds 591 — WEX Latin America debt 17,052 16,242 Total gross debt $ 3,027,671 $ 2,383,047 Current portion of gross debt $ 192,736 $ 223,241 Less: Unamortized debt issuance costs (8,379 ) (6,724 ) Short-term debt, net $ 184,357 $ 216,517 Long-term gross debt $ 2,834,935 $ 2,159,806 Less: Unamortized debt issuance costs (25,574 ) (25,883 ) Long-term debt, net $ 2,809,361 $ 2,133,923 Supplemental information under 2016 Credit Agreement: Letters of credit (b) $ 53,534 $ 53,514 Borrowing capacity on revolving credit facility (c) $ 547,260 $ 666,486 (a) See Note 11, Fair Value, for more information regarding the Company’s 2016 Credit Agreement and Notes. (b) Collateral for lease agreements, virtual card and fuel payment processing activity at the Company’s foreign subsidiaries. (c) Contingent on maintaining compliance with the financial covenants as defined in the Company’s 2016 Credit Agreement. 2016 Credit Agreement As of December 31, 2018, the 2016 Credit Agreement, as amended, provided for a secured tranche A term loan in an original principal amount of $480.0 million , a secured tranche B term loan in an original principal amount of $1,335.0 million and a $720.0 million secured revolving credit facility, with a $250.0 million sublimit for letters of credit and $20.0 million sublimit for swingline loans. Under the 2016 Credit Agreement, the Company has granted a security interest in substantially all of the assets of the Company, subject to exceptions including the assets of WEX Bank and certain foreign subsidiaries. On January 18, 2019, the Company entered into a Fifth Amendment to the 2016 Credit Agreement, which provided additional tranche A term loans in the principal amount of $300 million , increasing the outstanding principal on the tranche A term loans to $723.7 million as of such date. In addition, subject to certain conditions, the Fifth Amendment provided delayed draw commitments for an incremental $275.0 million tranche A term loan and an incremental $25.0 million of revolving credit commitments (subject to conversion of the delayed draw incremental tranche A term loan commitments and incremental revolving credit commitments to commitments of the other type). On March 5, 2019, the Company drew down this commitment in order to fund the acquisition of Discovery Benefits, consisting of $250.0 million of tranche A term loans and an incremental $50.0 million of revolving credit commitments. Amounts due under the 2016 Credit Agreement mature in July 2023, subject to earlier maturity as more fully described below. Prior to maturity, amounts borrowed under the credit facility will be reduced by mandatory quarterly payments of $12.5 million and $3.4 million for tranche A and tranche B term loan facilities, respectively. The revolving loans and tranche A loans outstanding under the 2016 Credit Agreement bear interest at variable rates, at the Company’s option, plus an applicable margin determined based on the Company’s consolidated leverage ratio. The tranche B loans bear interest at a variable rate plus a margin equal to 2.25 percent for base rate loans and 1.25 percent for eurocurrency rate loans. As of March 31, 2019 and December 31, 2018, amounts outstanding under the 2016 Credit Agreement bore a weighted average effective interest rate of 4.6 percent and 4.7 percent , respectively. The Company maintains interest rate swap agreements to manage the interest rate risk associated with its outstanding variable-interest rate borrowings under the 2016 Credit Agreement. See Note 7, Derivative Instruments, for further discussion. The Company accounted for the January 2019 Credit Agreement amendment as a debt modification. As part of this transaction, the Company incurred and expensed $4.4 million of third party costs, which are classified within general and administrative expenses in our unaudited condensed consolidated statements of income. In addition, the Company incurred and capitalized $3.4 million of lender costs associated with the January 2019 debt amendment. These debt issuance costs are being amortized into interest expense over the 2016 Credit Agreement’s term using the effective interest method. Debt Covenants As more fully described in the Company’s Annual Report on Form 10 – K for the year ended December 31, 2018, the 2016 Credit Agreement and the Indenture contain covenants that limit the ability of the Company and its subsidiaries, including 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. As of March 31, 2019, the Company was in compliance with all material covenants of its 2016 Credit Agreement and the Indenture. Notes Outstanding As of both March 31, 2019 and December 31, 2018 , the Company had $400.0 million of 4.75 percent fixed-rate senior notes outstanding, which will mature on February 1, 2023. Interest is payable semiannually in arrears on February 1 and August 1 of each year. Australian Securitization Facility The Company maintains a securitized debt agreement with the Bank of Tokyo-Mitsubishi UFJ, Ltd., which expires April 2019. Subsequent to March 31, 2019, this agreement was extended through April 2020. Under the terms of the agreement, each month, on a revolving basis, the Company sells certain of its Australian receivables to the Company’s Australian Securitization Subsidiary. The Australian Securitization Subsidiary, in turn, uses the receivables as collateral to issue asset-backed commercial paper (“securitized debt”) for approximately 85 percent of the securitized receivables. The amount collected on the securitized receivables is restricted to pay the securitized debt and is not available for general corporate purposes. The Company pays a variable interest rate on the outstanding balance of the securitized debt, based on the Australian Bank Bill Rate plus an applicable margin. The interest rate was 2.90 percent and 2.89 percent as of March 31, 2019 and December 31, 2018 , respectively. The Company had $78.7 million and $87.0 million of securitized debt under this facility as of March 31, 2019 and December 31, 2018 , respectively. European Securitization Facility On April 7, 2016, the Company entered into a five year securitized debt agreement with the Bank of Tokyo-Mitsubishi UFJ, Ltd. Under the terms of the agreement, the Company sells certain of its receivables from selected European countries to its European Securitization Subsidiary. The European Securitization Subsidiary, in turn, uses the receivables as collateral to issue securitized debt. The amount collected on the securitized receivables is restricted to pay the securitized debt and is not available for general corporate purposes. The amounts of receivables to be securitized under this agreement is determined by management on a monthly basis. The interest rate was 0.87 percent and 0.98 percent as of March 31, 2019 and December 31, 2018 , respectively. The Company had $26.4 million and $18.0 million of securitized debt under this facility as of March 31, 2019 and December 31, 2018 , respectively. Participation Debt From time to time, WEX Bank enters into participation agreements with third-party banks to fund customers’ balances that exceed WEX Bank’s lending limit to individual customers. Associated unsecured borrowings carry a variable interest rate of 1 month to 3 month LIBOR plus a margin of 225 basis points. The following table provides the amounts outstanding under the participation debt agreements in place: March 31, 2019 December 31, 2018 (In thousands) Amounts Outstanding Remaining Funding Capacity Amounts Outstanding Remaining Funding Capacity Short-term debt, net (a) $ 5,677 $ 124,323 $ 64,849 $ 65,151 Long-term debt, net (b) $ 50,000 $ — $ 50,000 $ — Average interest rate 4.85 % 4.30 % (a) Amounts outstanding under agreements terminating on June 30, 2019 and on demand. (b) Amounts outstanding under an agreement terminating on August 31, 2020. Borrowed Federal Funds WEX Bank borrows from uncommitted federal funds lines to supplement the financing of the Company’s accounts receivable. Our federal funds lines of credit were $327.4 million and $309.0 million as of March 31, 2019 and December 31, 2018 , respectively. As of March 31, 2019 there were outstanding borrowings of $0.6 million at an interest rate of 2.64 percent . There were no outstanding borrowings as of December 31, 2018 . WEX Latin America Debt WEX Latin America had debt of approximately $17.1 million and $16.2 million as of March 31, 2019 and December 31, 2018 , respectively. This is comprised of credit facilities and loan arrangements related to our accounts receivable. These borrowings are recorded in short-term debt, net on the Company’s unaudited condensed consolidated balance sheets. As of March 31, 2019 and December 31, 2018 , the interest rate was 24.74 percent and 23.59 percent , respectively.

Off-Balance Sheet Arrangements

Off-Balance Sheet Arrangements	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Off-Balance Sheet Arrangements	10. Off–Balance Sheet Arrangements WEX Europe Services Accounts Receivable Factoring During the first quarter of 2017, WEX Europe Services entered into a factoring arrangement with an unrelated third-party financial institution (the “Purchasing Bank”). Under this arrangement, the Purchasing Bank establishes a credit limit for each customer account. The factored receivables are without recourse to the extent that the customer balances are maintained at or below the established credit limit. For customer receivable balances in excess of the Purchasing Bank’s credit limit, the Company maintains the risk of default. Additionally, there are no indications of the Company’s continuing involvement in the factored receivables. The Company obtained a true-sale opinion from an independent attorney, which states that the factoring agreement provides legal isolation upon WEX Europe Services bankruptcy or receivership under local law and creates a sale of receivables for amounts transferred both below and above the established credit limits. As such, transfers under this arrangement are treated as sales and are accounted for as reductions in trade receivables because the agreements transfer effective control of the receivables to the Purchasing Bank. The Company records the proceeds as cash provided by operating activities. The Company sold approximately $150.0 million and $170.2 million of receivables under this arrangement during the three months ended March 31, 2019 and March 31, 2018 , respectively. Proceeds received are recorded net of applicable expenses, interest and commissions. The loss on factoring was $0.8 million and $1.1 million for the three months ended March 31, 2019 and 2018, respectively, and was recorded within cost of services in the unaudited condensed consolidated statements of income. As of March 31, 2019 and December 31, 2018 , an immaterial amount of outstanding transferred receivables were in excess of the established credit limit. Charge-backs on balances in excess of the credit limit during the three months ended March 31, 2019 and during the three months ended March 31, 2018 were insignificant. WEX Bank Accounts Receivable Factoring In August 2018, WEX Bank entered into a receivables purchase agreement with an unrelated third-party financial institution to sell certain of our trade receivables under non-recourse transactions. WEX Bank continues to service the receivables post-transfer with no participating interest. The Company obtained a true-sale opinion from an independent attorney, which states that the factoring agreement provides legal isolation upon WEX Bank bankruptcy or receivership under local law. As such, transfers under this arrangement are treated as a sale and are accounted for as a reduction in trade receivables because the agreements transfer effective control of the receivables to the buyer. The Company sold approximately $2.0 billion of receivables under this arrangement during the three months ended March 31, 2019 . Proceeds from the sale, which are reported net of a negotiated discount rate, are recorded in operating activities within the Company’s unaudited condensed consolidated statement of cash flows. The loss on factoring was $0.6 million for the three months ended March 31, 2019 and was recorded within cost of services in the unaudited condensed consolidated statements of income. WEX Latin America Securitization of Receivables During the second quarter of 2017, WEX Latin America entered into a securitized debt agreement to transfer certain unsecured receivables associated with our salary payment card product to an investment fund managed by an unrelated third-party financial institution. WEX Latin America holds a non-controlling equity interest in the investment fund. During the three months ended March 31, 2019 , the Company did not make equity contributions to the investment fund. As of December 31, 2017 and through June 30, 2018, this securitization arrangement did not meet the derecognition conditions due to continuing involvement with the transferred assets and accordingly WEX Latin America reported the transferred receivables and securitized debt on our unaudited condensed consolidated balance sheets. During the three months ended March 31, 2018, the Company recognized approximately $2.1 million of operating interest expense under this financing arrangement. During the third quarter of 2018, the securitization agreements were amended, resulting in the Company giving up effective control of the transferred receivables to the buyer. Additionally, the Company received a true-sale opinion from an independent attorney stating that the amended agreements provide legal isolation upon WEX Latin America bankruptcy or receivership under local law. As such, transfers under this arrangement are treated as a sale and are accounted for as a reduction in trade receivables. During the three months ended March 31, 2019 , the Company sold $20.7 million of receivables and recognized a $3.7 million gain on sale, consisting of the difference between the sales price and the carrying value of the receivables, which is recorded within other revenue in our unaudited condensed consolidated statement of income. Cash proceeds from the transfer of these receivables is reflected as an operating activity within our unaudited condensed consolidated statement of cash flows.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value	11. Fair Value The Company holds mortgage-backed securities, fixed-income securities, money market funds, derivatives (see Note 7, Derivative Instruments ) and certain other financial instruments that 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. Various factors are considered in determining the fair value of the Company’s obligations, 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 in active markets. • Level 2 – Quoted prices for similar instruments in active 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. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. We did not have any transfers between Level 1 and Level 2 of the fair value hierarchy during either of the three months ended March 31, 2019 or March 31, 2018 . Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents the Company’s financial instruments that are measured at fair value: (In thousands) Fair Value Hierarchy March 31, 2019 December 31, 2018 Financial Assets: Money market funds (a) 1 $ 5,991 $ 71,228 Investment securities Municipal bonds 2 $ 334 $ 404 Asset-backed securities 2 271 279 Mortgage-backed securities 2 268 260 Fixed-income mutual fund 1 23,899 23,463 Total investment securities $ 24,772 $ 24,406 Executive deferred compensation plan trust (b) 1 $ 7,585 $ 6,398 Interest rate swaps (c) 2 $ 10,805 $ 17,994 Liabilities Interest rate swaps (d) 2 $ 5,020 $ — (a) The fair value is recorded in cash and cash equivalents. (b) The fair value is recorded in prepaid expenses and other current assets and other assets based on the timing of payment obligations. (c) The fair value is recorded in prepaid expenses and other current assets or other assets depending on the timing of expected discounted cash flows. (d) The fair value is recorded in other current liabilities or other liabilities depending on the timing of expected discounted cash flows. Money Market Funds A portion of the Company’s cash and cash equivalents are invested in a money market fund that primarily consists of short-term government securities, which are classified as Level 1 in the fair value hierarchy because they are valued using quoted market prices in an active market. Investment Securities When available, the Company uses quoted market prices to determine the fair value of investment securities; such inputs are classified as Level 1 of the fair-value hierarchy. These securities primarily consist of an open-ended mutual fund, which is invested in fixed-income securities and is held in order to satisfy the regulatory requirements of WEX Bank. For mortgage-backed and asset-backed debt securities and municipal 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 valued using Level 2 inputs. Executive Deferred Compensation Plan Trust The investments held in the executive deferred compensation plan trust are classified as Level 1 in the fair value hierarchy because the fair value is determined using quoted prices for identical instruments in active markets. Interest Rate Swaps The Company determines the fair value of its interest rate swaps based on the discounted cash flows of the difference between the projected fixed payments on the swaps and the implied floating payments using the current LIBOR curve, which are Level 2 inputs of the fair value hierarchy. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Notes Outstanding The Notes outstanding had a fair value of $399.0 million and $392.0 million as of March 31, 2019 and December 31, 2018 , respectively. The fair value of the Notes is based on market rates for the issuance of our debt and is classified as Level 2 in the fair value hierarchy. 2016 Credit Agreement The Company determines the fair value of the amount outstanding under its 2016 Credit Agreement based on the market rates for the issuance of the Company’s debt, which are Level 2 inputs in the fair value hierarchy. As of both March 31, 2019 and December 31, 2018 , the carrying value of the 2016 Credit Agreement approximated its fair value. Other Assets and Liabilities Our financial instruments, other than those presented above, include cash and cash equivalents, accounts receivable, accounts payable, accrued expenses and other liabilities. The carrying values of such assets and liabilities approximate their respective fair values due to their short-term nature. The carrying values of certificates of deposit, interest-bearing brokered money market deposits, securitized debt, participation debt and borrowed federal funds approximate their respective fair values, as the interest rates on these financial instruments are variable market-based rates. All other financial instruments are reflected at fair value on the unaudited condensed consolidated balance sheets.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interest	3 Months Ended
	Mar. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Non-Controlling Interest	12. Redeemable Non-Controlling Interest On March 5, 2019, the Company acquired Discovery Benefits, an employee benefits administrator. The seller of Discovery Benefits obtained a 4.9 percent equity interest in the newly formed parent company of WEX Health and Discovery Benefits (“the U.S. Health business”). The seller’s 4.9 percent non-controlling interest in WEX Health and DBI was initially established at carrying value and fair value, respectively. On the date of acquisition, the excess of the fair value of the 4.9 percent equity interest in WEX Health over its carrying value was recognized as an equity transaction, resulting in a $41.4 million increase to additional paid-in capital. The agreement provides the seller with a put right and the Company with a call right for the equity interest, which can be exercised no earlier than five and seven years following the date of acquisition, respectively. Upon exercise of the put or call right, the purchase price is calculated based on a revenue multiple of peer companies (as defined in the agreement) applied to trailing twelve month revenues of the U.S. Health business. The put option makes the non-controlling interest redeemable and, therefore, the non-controlling interest is classified as temporary equity outside of stockholders’ equity. The redeemable non-controlling interest is reported at the higher of its redemption value or the non-controlling interest holder’s proportionate share of the U.S. Health business’ net carrying value. Subsequent remeasurement of the equity interest to fair value resulted in an increase to redeemable non-controlling interest of $41.4 million and an offsetting decrease to retained earnings that did not impact earnings per share. As of March 31, 2019, the carrying amount for this redeemable non-controlling interest was greater than the redemption value, resulting in no adjustment to reflect the non-controlling interest at redemption value. Subsequent increases or decreases in the redemption value of the non-controlling interest will be offset against retained earnings and impact earnings per share. The following table presents the changes in the Company’s redeemable non-controlling interest: (In thousands) Three months ended March 31, 2019 Balance, beginning of period $ — Acquisition of Discovery Benefits at fair value 25,757 Establishing redeemable non-controlling interest for WEX Health at carrying value 32,843 Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value 41,400 Net loss attributable to redeemable non-controlling interest (7 ) Balance, end of period $ 99,993

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes The Company’s effective tax rate was 26.4 percent for the first quarter of 2019 as compared to 25.2 percent for the first quarter of 2018. The increase in our tax rate was primarily due to the increase in unrecognized tax benefits in 2019. While our accounting for the impact of the 2017 Tax Cut and Jobs Act (“TCJA”) as of December 31, 2018 was deemed to be complete, amounts recorded were based on prevailing regulations and available information as of December 31, 2018. Additional guidance issued by the Internal Revenue Service (“IRS”) may continue to impact our recorded amounts after December 31, 2018. Undistributed earnings of certain foreign subsidiaries of the Company amounted to $77.0 million and $64.9 million at March 31, 2019 and December 31, 2018 , respectively. These earnings and profits are considered to be indefinitely reinvested. Upon distribution of these earnings in the form of dividends or otherwise, the Company would be subject to withholding taxes payable, where applicable, to foreign countries, but would have no further federal income tax liability.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	14. Leases We have operating leases for buildings, primarily for office space. For building leases with terms greater than twelve months, we account for lease and non-lease components as a single lease component. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Short-term lease payments are recognized on a straight-line basis and variable short-term lease payments are recognized in the period in which the obligation is incurred. We determine whether or not a contract contains a lease at inception of the contract. Many of our lease agreements contain renewal or termination clauses that we factor into our determination of the lease term if we are reasonably certain to exercise any such options. The following table presents supplemental balance sheet information related to our leases: (In thousands) Balance Sheet Location March 31, 2019 Assets Operating lease ROU assets Other assets $ 80,806 Liabilities Current operating lease liabilities Other current liabilities 12,135 Non-current operating lease liabilities Other liabilities 80,320 Total lease liabilities $ 92,455 The following table presents the weighted average remaining lease term and discount rate: Operating leases March 31, 2019 Weighted average remaining term (in years) 8.7 Weighted average discount rate 4.6 % The following table presents the maturities of our lease liabilities: (In thousands) March 31, 2019 Remaining 2019 $ 12,070 2020 15,275 2021 14,810 2022 13,420 2023 11,238 2024 and thereafter 47,688 Total lease payments $ 114,501 Less: Imputed interest 22,046 Total lease obligations $ 92,455 Less: Current portion of lease obligations 12,135 Long-term lease obligations $ 80,320 In addition to the total lease obligations presented in the table above, we have a 14 year building operating lease with undiscounted payment obligations of $30.0 million that is expected to commence during 2020. We recognized $4.0 million of operating lease expense during the three months ended March 31, 2019, which includes immaterial short-term leases and variable lease costs. These amounts are classified as general and administrative expense on our unaudited condensed consolidated statements of income. The following table presents supplemental cash flow and other information related to our leases: (In thousands) March 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 4,075 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 14,646

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	15. Commitments and Contingencies Litigation The Company is subject to legal proceedings and claims in the ordinary course of business. As of the date of this filing, the current estimate of a reasonably possible loss contingency from all legal proceedings is not material to the Company’s consolidated financial position, results of operations, cash flows or liquidity. Commitments Significant commitments and contingencies as of March 31, 2019 are consistent with those discussed in Note 19, Commitments and Contingencies, to the consolidated financial statements in the Annual Report on Form 10–K for the year ended December 31, 2018 .

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	16. Stock–Based Compensation The fair value of restricted stock units (“RSUs”), DSUs, performance-based restricted stock units (“PBRSUs”) and service-based stock options awarded during the three months ended March 31, 2019 totaled $38.1 million , as compared to $27.4 million for the three months ended March 31, 2018 . The fair value of RSUs, DSUs and PBRSUs is based on the closing market price of the Company’s stock on the grant date as reported by the NYSE. The fair value of each service-based stock option award is estimated on the grant date using a Black-Scholes-Merton option-pricing model. The table below presents the weighted average fair value of service-based stock options by year of grant and the assumptions used in estimating those fair values: 2019 2018 Weighted average fair value $ 58.28 $ 51.27 Weighted average expected life (in years) 6.0 6.0 Weighted average exercise price $ 184.81 $ 158.23 Expected stock price volatility 27.21 % 27.35 % Risk-free interest rate 2.37 % 2.69 %

Restructuring Activities

Restructuring Activities	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring Activities	17. Restructuring Activities In the first quarter of 2015, the Company commenced a restructuring initiative (the “2015 Restructuring Initiative”) as a result of its global review of operations. The review of operations identified certain initiatives to further streamline the business, improve the Company’s efficiency and globalize the Company’s operations, all with an objective to improve scale and increase profitability going forward. The Company continued its efforts to improve its overall operational efficiency and began a second restructuring initiative (the “2016 Restructuring Initiative”) during the second quarter of 2016. In connection with the EFS acquisition, the Company initiated a third restructuring program in the third quarter of 2016 (the “Acquisition Integration Restructuring Initiative”). Total restructuring charges incurred to date under these initiatives, which primarily consisted of employee costs and office closure costs, were $24.8 million as of March 31, 2019 . Restructuring charges incurred during the three months ended March 31, 2019 and 2018 were immaterial. Based on current plans, which are subject to change, the Company does not expect to incur any material charges under these initiatives.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment Information	18. Segment Information The Company determines its operating segments and reports information in accordance with how the Company’s chief operating decision maker (“CODM”) allocates resources and assesses performance. The Company’s CODM is its Chief Executive Officer. The operating segments are aggregated into the three reportable segments described below. • Fleet Solutions primarily provides customers with payment and transaction processing services specifically designed for the needs of commercial and government fleets. This segment also provides information management services to these fleet customers. • Travel and Corporate Solutions focuses on the complex payment environment of business-to-business payments, providing customers with payment processing solutions for their corporate payment and transaction monitoring needs. • Health and Employee Benefit Solutions provides healthcare payment products and SaaS consumer directed platforms, as well as payroll related benefits to customers. The following tables present the Company’s reportable segment revenues: Three Months Ended March 31, 2019 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Revenues Payment processing revenue $ 107,408 $ 59,998 $ 19,392 $ 186,798 Account servicing revenue 39,239 10,585 37,262 87,086 Finance fee revenue 45,864 357 152 46,373 Other revenue 40,271 10,708 10,640 61,619 Total revenues $ 232,782 $ 81,648 $ 67,446 $ 381,876 Interest income $ 2,221 $ 377 $ 159 $ 2,757 Three Months Ended March 31, 2018 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Revenues Payment processing revenue $ 106,978 $ 44,777 $ 16,699 $ 168,454 Account servicing revenue 42,210 9,469 27,025 78,704 Finance fee revenue 43,604 259 5,018 48,881 Other revenue 37,573 12,274 8,142 57,989 Total revenues $ 230,365 $ 66,779 $ 56,884 $ 354,028 Interest income $ 995 $ 421 $ 5,967 $ 7,383 The CODM evaluates the financial performance of each segment using segment adjusted operating income, which excludes: (i) acquisition and divestiture related items (including acquisition-related intangible amortization); (ii) debt restructuring costs; (iii) stock-based compensation; (iv) restructuring and other costs; and (v) unallocated corporate expenses. Additionally, we do not allocate foreign currency gains and losses, financing interest expense, unrealized and realized gains and losses on financial instruments, income taxes and net gains or losses from non-controlling interests to our operating segments. The following table reconciles segment adjusted operating income to income before income taxes: Three Months Ended March 31, (In thousands) 2019 2018 Segment adjusted operating income Fleet Solutions $ 92,975 $ 107,973 Travel and Corporate Solutions 34,387 25,249 Health and Employee Benefit Solutions 19,780 18,071 Total segment adjusted operating income $ 147,142 $ 151,293 Reconciliation: Total segment adjusted operating income $ 147,142 $ 151,293 Less: Unallocated corporate expenses 16,942 13,920 Acquisition-related intangible amortization 33,888 35,236 Other acquisition and divestiture related items 9,780 637 Debt restructuring costs 4,400 3,015 Stock-based compensation 10,442 8,955 Restructuring and other costs 2,755 5,671 Operating income 68,935 83,859 Financing interest expense (31,112 ) (27,337 ) Net foreign currency (loss) gain (3,885 ) 390 Net unrealized (loss) gain on financial instruments (11,912 ) 13,508 Income before income taxes $ 22,026 $ 70,420

Supplementary Regulatory Capita

Supplementary Regulatory Capital Disclosure	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Supplementary Regulatory Capital Disclosure	19. Supplementary Regulatory Capital Disclosure The Company’s subsidiary, WEX Bank, is subject to various regulatory capital requirements administered by the FDIC and the Utah Department of Financial Institutions. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, WEX Bank must meet specific capital guidelines that involve quantitative measures of WEX Bank’s assets, liabilities and certain off-balance sheet items. WEX Bank’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Failure to meet minimum capital requirements can initiate certain mandatory and possible additional discretionary actions by regulators that, if undertaken, could limit our business activities and have a material effect on our business, results of operations and financial condition. Quantitative measures established by regulation to ensure capital adequacy require WEX Bank to maintain minimum amounts and ratios as defined in the regulations. As of March 31, 2019 , the most recent FDIC exam report categorized WEX Bank as “well capitalized” under the regulatory framework for prompt corrective action. There are no conditions or events subsequent to that examination report that management believes have changed WEX Bank’s capital rating. The following table presents WEX Bank’s actual and regulatory minimum capital amounts and ratios: (In thousands) Actual Amount Ratio Minimum for Capital Adequacy Purposes Amount Ratio Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio March 31, 2019 Total Capital to risk-weighted assets $ 317,780 12.01 % $ 211,640 8.0 % $ 264,550 10.0 % Tier 1 Capital to average assets $ 302,413 10.92 % $ 110,746 4.0 % $ 138,432 5.0 % Common equity to risk-weighted assets $ 302,413 11.43 % $ 119,048 4.5 % $ 171,958 6.5 % Tier 1 Capital to risk-weighted assets $ 302,413 11.43 % $ 158,730 6.0 % $ 211,640 8.0 % December 31, 2018 Total Capital to risk-weighted assets $ 323,178 12.82 % $ 201,749 8.0 % $ 252,186 10.0 % Tier 1 Capital to average assets $ 305,734 10.88 % $ 112,401 4.0 % $ 140,501 5.0 % Common equity to risk-weighted assets $ 305,734 12.12 % $ 113,484 4.5 % $ 163,921 6.5 % Tier 1 Capital to risk-weighted assets $ 305,734 12.12 % $ 151,312 6.0 % $ 201,749 8.0 %

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10–Q and Rule 10–01 of Regulation S–X. Accordingly, they do not include all information and notes required by GAAP for complete financial statements. 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, 2018 , filed with the SEC on March 18, 2019 and our Form 10–K/A filed with the SEC on March 20, 2019. 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 months ended March 31, 2019 are not necessarily indicative of the results for any future periods or the year ending December 31, 2019 . Effective January 1, 2019, the Company modified the presentation of the unaudited condensed balance sheets to separately classify its restricted cash payable. The prior period has been reclassified to conform with this presentation. There was no change to current liabilities as a result of this change. We apply the same accounting policies in preparing our quarterly and annual financial statements, with the exception of the new leasing standard which is required to be adopted on a prospective basis. Refer to Note 2, Recent Accounting Pronouncements, for more information. The Company rounds amounts in the unaudited condensed consolidated financial statements to thousands and calculates all per-share data from underlying whole-dollar amounts. Thus, certain amounts may not foot, crossfoot or recalculate based on reported numbers due to rounding.
New Accounting Standards	Standard Description Date/Method of Adoption Effect on financial statements or other significant matters Adopted During the Three Months Ended March 31, 2019 ASU 2016–02 This standard requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The Company adopted ASU 2016–02 effective January 1, 2019, using the modified retrospective approach, and all practical expedients permitted under the transition guidance. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016–02, Leases (Topic 842), which requires leases with a duration greater than twelve months to be recognized on the balance sheet as right-of-use (“ROU”) assets and lease liabilities. We adopted the new standard using the modified retrospective approach and have elected the package of practical expedients permitted under the transition guidance, including the hindsight practical expedients for expired or existing contracts, which allowed us to carryforward our historical determination of (i) whether a contract is or contains a lease, (ii) lease classification and (iii) initial direct costs. Additionally, we elected the practical expedients which allowed us to (i) not perform an allocation of lease and non-lease components for real estate leases, (ii) continue to account for short-term leases under Topic 840 and (iii) utilize our incremental borrowing rate (“IBR”), rather than the rate implicit in each lease, to calculate the present value of the remaining lease payments. As such, the unaudited condensed consolidated financial statements for the period ended March 31, 2019 are presented under the new standard, while comparative periods presented continue to be reported in accordance with Topic 840. The most significant impact of adoption was the recording of operating lease ROU assets and operating lease liabilities on our unaudited condensed consolidated balance sheets at January 1, 2019. Refer to Note 14, Leases, for more information. The standard did not materially impact our results of operations or cash flows. ASU 2018 – 15 This standard clarifies the accounting for capitalizing implementation costs in a cloud computing arrangement that is a service contract. The standard provides that implementation costs be treated using the same criteria used for internal-use software development costs, with amortization expense being recorded in the same income statement expense line as the hosted service costs and over the expected term of the hosting arrangement. Effective January 1, 2019, the Company early adopted ASU 2018–15 on a prospective basis. Under the standard, we now capitalize implementation costs related to our cloud migration of technology platforms to the cloud. Such amounts are amortized over the lesser of the term of the hosting arrangement, considering any explicit renewal options for which we are reasonably certain to exercise, or the useful life of the underlying hosted software. We do not expect that adoption of this standard will have a material impact on our results of operations, cash flows or consolidated financial position. Not Yet Adopted as of March 31, 2019 ASU 2016 – 13 This standard requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses will be based on historical experience, current conditions and reasonable and supportable forecasts that impact the collectability of the reported amount. The standard is effective January 1, 2020. The Company is evaluating the impact the standard will have on its consolidated financial statements and related disclosures.
Receivables	In general, the Company’s trade receivables provide for payment terms of 30 days or less. Receivables not paid within the terms of the agreement are generally subject to late fees based upon the outstanding receivable balance. The Company extends revolving credit to certain small fleets, which are subject to interest charges based on the revolving balance not paid in full.
Earnings per Share	Basic earnings per share is computed by dividing net income attributable to shareholders by the weighted average number of shares of common stock and vested deferred stock units (“DSUs”) outstanding during the year. The computation of diluted earnings per share is similar to the computation of basic earnings per share, except that the denominator is increased for the assumed exercise of dilutive options and assumed issuance of unvested performance-based awards for which the performance condition has been met as of the date of determination using the treasury stock method unless the effect is anti-dilutive. The treasury stock method assumes that proceeds, including cash received from the exercise of employee stock options and the average unrecognized compensation expense for unvested share-based compensation awards, would be used to purchase the Company’s common stock at the average market price during the period.
Derivative Instruments	The Company is exposed to certain market risks relating to its ongoing business operations. From time to time, the Company enters into derivative instrument arrangements to manage various risks including interest rate risk
Fair Value of Financial Instruments	The Company holds mortgage-backed securities, fixed-income securities, money market funds, derivatives (see Note 7, Derivative Instruments ) and certain other financial instruments that 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. Various factors are considered in determining the fair value of the Company’s obligations, 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 in active markets. • Level 2 – Quoted prices for similar instruments in active 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. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The fair value of the Notes is based on market rates for the issuance of our debt and is classified as Level 2 in the fair value hierarchy. Investment Securities When available, the Company uses quoted market prices to determine the fair value of investment securities; such inputs are classified as Level 1 of the fair-value hierarchy. These securities primarily consist of an open-ended mutual fund, which is invested in fixed-income securities and is held in order to satisfy the regulatory requirements of WEX Bank. For mortgage-backed and asset-backed debt securities and municipal 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 valued using Level 2 inputs. 2016 Credit Agreement The Company determines the fair value of the amount outstanding under its 2016 Credit Agreement based on the market rates for the issuance of the Company’s debt, which are Level 2 inputs in the fair value hierarchy.
Leases	We have operating leases for buildings, primarily for office space. For building leases with terms greater than twelve months, we account for lease and non-lease components as a single lease component. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Short-term lease payments are recognized on a straight-line basis and variable short-term lease payments are recognized in the period in which the obligation is incurred. We determine whether or not a contract contains a lease at inception of the contract. Many of our lease agreements contain renewal or termination clauses that we factor into our determination of the lease term if we are reasonably certain to exercise any such options.
Segment Information	The Company determines its operating segments and reports information in accordance with how the Company’s chief operating decision maker (“CODM”) allocates resources and assesses performance. The Company’s CODM is its Chief Executive Officer. The operating segments are aggregated into the three reportable segments described below. • Fleet Solutions primarily provides customers with payment and transaction processing services specifically designed for the needs of commercial and government fleets. This segment also provides information management services to these fleet customers. • Travel and Corporate Solutions focuses on the complex payment environment of business-to-business payments, providing customers with payment processing solutions for their corporate payment and transaction monitoring needs. • Health and Employee Benefit Solutions provides healthcare payment products and SaaS consumer directed platforms, as well as payroll related benefits to customers.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Error Corrections and Prior Period Adjustments	The effects of the Revision on our unaudited condensed consolidated statements of income and cash flows were as follows: Three months ended March 31, 2018 (In thousands, except per share data) As Previously Reported Brazil Adjustments Other Immaterial Adjustments As Revised Total revenues $ 354,829 $ (801 ) $ — $ 354,028 Processing costs $ 79,640 $ (6,534 ) $ — $ 73,106 Provision for credit losses $ 13,990 $ 236 $ — $ 14,226 Operating income $ 78,362 $ 5,497 $ — $ 83,859 Income taxes $ 15,589 $ 2,343 $ (183 ) $ 17,749 Net income $ 49,334 $ 3,154 $ 183 $ 52,671 Net income attributable to shareholders $ 48,633 $ 3,154 $ 183 $ 51,970 Net income attributable to WEX Inc. per share Basic $ 1.13 $ 0.08 $ — $ 1.21 Diluted $ 1.12 $ 0.08 $ — $ 1.20 Three months ended March 31, 2018 (In thousands) As Previously Reported Brazil Adjustments Other Immaterial Adjustments As Revised Net cash provided by operating activities $ 85,243 $ — $ 2,563 $ 87,806 Effect of exchange rates on cash, cash equivalents and restricted cash $ (2,577 ) $ — $ 1,990 $ (587 ) Cash, cash equivalents and restricted cash, beginning of period $ 526,938 $ — $ (4,553 ) $ 522,385

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Tables)	3 Months Ended
	Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table provides a brief description of accounting pronouncements adopted during the three months ended March 31, 2019 and recent accounting pronouncements that could have a material effect on our financial statements: Standard Description Date/Method of Adoption Effect on financial statements or other significant matters Adopted During the Three Months Ended March 31, 2019 ASU 2016–02 This standard requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The Company adopted ASU 2016–02 effective January 1, 2019, using the modified retrospective approach, and all practical expedients permitted under the transition guidance. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016–02, Leases (Topic 842), which requires leases with a duration greater than twelve months to be recognized on the balance sheet as right-of-use (“ROU”) assets and lease liabilities. We adopted the new standard using the modified retrospective approach and have elected the package of practical expedients permitted under the transition guidance, including the hindsight practical expedients for expired or existing contracts, which allowed us to carryforward our historical determination of (i) whether a contract is or contains a lease, (ii) lease classification and (iii) initial direct costs. Additionally, we elected the practical expedients which allowed us to (i) not perform an allocation of lease and non-lease components for real estate leases, (ii) continue to account for short-term leases under Topic 840 and (iii) utilize our incremental borrowing rate (“IBR”), rather than the rate implicit in each lease, to calculate the present value of the remaining lease payments. As such, the unaudited condensed consolidated financial statements for the period ended March 31, 2019 are presented under the new standard, while comparative periods presented continue to be reported in accordance with Topic 840. The most significant impact of adoption was the recording of operating lease ROU assets and operating lease liabilities on our unaudited condensed consolidated balance sheets at January 1, 2019. Refer to Note 14, Leases, for more information. The standard did not materially impact our results of operations or cash flows. ASU 2018 – 15 This standard clarifies the accounting for capitalizing implementation costs in a cloud computing arrangement that is a service contract. The standard provides that implementation costs be treated using the same criteria used for internal-use software development costs, with amortization expense being recorded in the same income statement expense line as the hosted service costs and over the expected term of the hosting arrangement. Effective January 1, 2019, the Company early adopted ASU 2018–15 on a prospective basis. Under the standard, we now capitalize implementation costs related to our cloud migration of technology platforms to the cloud. Such amounts are amortized over the lesser of the term of the hosting arrangement, considering any explicit renewal options for which we are reasonably certain to exercise, or the useful life of the underlying hosted software. We do not expect that adoption of this standard will have a material impact on our results of operations, cash flows or consolidated financial position. Not Yet Adopted as of March 31, 2019 ASU 2016 – 13 This standard requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses will be based on historical experience, current conditions and reasonable and supportable forecasts that impact the collectability of the reported amount. The standard is effective January 1, 2020. The Company is evaluating the impact the standard will have on its consolidated financial statements and related disclosures.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Summary of Disaggregation of Revenue	The following table disaggregates our consolidated revenue for the three months ended March 31, 2019 : Three Months Ended March 31, 2019 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Topic 606 revenues Payment processing revenue $ 107,408 $ 59,998 $ 19,392 $ 186,798 Account servicing revenue 6,800 10,585 37,262 54,647 Other revenue 16,986 1,105 6,776 24,867 Total Topic 606 revenues $ 131,194 $ 71,688 $ 63,430 $ 266,312 Non-Topic 606 revenues Account servicing revenue $ 32,439 $ — $ — $ 32,439 Finance fee revenue 45,864 357 152 46,373 Other revenue 23,285 9,603 3,864 36,752 Total non-Topic 606 revenues $ 101,588 $ 9,960 $ 4,016 $ 115,564 Total revenues $ 232,782 $ 81,648 $ 67,446 $ 381,876 The following table disaggregates our consolidated revenue for the three months ended March 31, 2018 : Three Months Ended March 31, 2018 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Topic 606 revenues Payment processing revenue $ 106,978 $ 44,777 $ 16,699 $ 168,454 Account servicing revenue 8,466 9,469 27,025 44,960 Other revenue 17,042 1,117 8,142 26,301 Total Topic 606 revenues $ 132,486 $ 55,363 $ 51,866 $ 239,715 Non-Topic 606 revenues Account servicing revenue $ 33,744 — — $ 33,744 Finance fee revenue 43,604 259 5,018 48,881 Other revenue 20,531 11,157 — 31,688 Total non-Topic 606 revenues $ 97,879 $ 11,416 $ 5,018 $ 114,313 Total revenues $ 230,365 $ 66,779 $ 56,884 $ 354,028
Summary of Contract Assets and Liabilities	The following table provides information about these contract balances. (In thousands) Contract balance Location on the unaudited condensed consolidated balance sheets March 31, 2019 December 31, 2018 Receivables 1 Accounts receivable, net $ 41,092 $ 32,949 Contract assets Prepaid expenses and other current assets $ 5,576 $ 3,819 Contract assets Other assets $ 20,280 $ 19,232 Contract liabilities Other current liabilities $ 6,594 $ 7,612 1 The majority of the Company’s receivables, which are excluded from the table above, are either due from cardholders, who have not been deemed our customer as it relates to interchange income, or from revenues earned outside of the scope of Topic 606.
Schedule of Remaining Performance Obligations	The following table includes revenue expected to be recognized related to remaining performance obligations at the end of the reporting period. (In thousands) Remaining 2019 2020 2021 2022 2023 2024 Total Minimum monthly fees 1 $ 45,776 $ 40,285 $ 23,227 $ 12,313 $ 3,753 $ 639 $ 125,993 Professional services 2 11,655 515 — — — — 12,170 Total remaining performance obligations $ 57,431 $ 40,800 $ 23,227 $ 12,313 $ 3,753 $ 639 $ 138,163 1 The transaction price allocated to the remaining performance obligations represents the minimum monthly fees on certain service contracts, which contain substantive termination penalties that require the counterparty to pay the Company for the aggregate remaining minimum monthly fees upon an early termination for convenience. 2 Includes software development projects and other services sold subsequent to the core offerings, to which the customer is contractually obligated.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions	The following is a summary of the preliminary allocation of the purchase price to the assets and liabilities acquired, based on the estimated fair value at the date of acquisition: (In thousands) Cash consideration, net of cash and restricted cash acquired of $125,865 $ 249,781 Fair value of redeemable non-controlling interest 100,000 Deferred cash consideration 50,000 Total consideration, net of cash and restricted cash acquired $ 399,781 Less: Accounts receivable 10,367 Property and equipment 4,904 Customer relationships (a)(d) 213,600 Developed technologies (b)(d) 38,900 Trademarks and trade names (c)(d) 13,800 Other assets 13,589 Accounts payable (3,024 ) Accrued expenses (7,399 ) Restricted cash payable (125,346 ) Deferred income taxes (22,200 ) Other liabilities (10,015 ) Recorded goodwill $ 272,605 (a) Weighted average life - 7.3 years . (b) Weighted average life - 5.4 years . (c) Weighted average life - 7.3 years . (d) The weighted average life of all amortizable intangible assets acquired in this business combination is 7.0 years . The following is a summary of the preliminary allocation of the purchase price to the assets and liabilities acquired, based on the estimated fair value at the date of acquisition: (In thousands) Total consideration, net of cash and restricted cash acquired of $51,538 $ 291,564 Less: Accounts receivable 23,002 Property and equipment 549 Network relationships (a) (c) 100,900 Developed technologies (b) (c) 15,000 Other assets 2,487 Accounts payable (36,794 ) Deferred income tax liabilities (24,121 ) Other liabilities (2,518 ) Recorded goodwill $ 213,059 (a) Weighted average life - 8.3 years . (b) Weighted average life - 2.9 years . (c) The weighted average life of all amortizable intangible assets acquired in this business combination is 7.6 years .
Business Acquisition, Pro Forma Information	The following represents unaudited pro forma operational results as if the acquisitions had occurred January 1, 2018: Three Months Ended March 31, 2019 2018 Total revenues $ 400,982 $ 381,826 Net income attributable to shareholders $ 18,810 $ 42,487 Net income attributable to WEX Inc. per share: Basic $ 0.44 $ 0.99 Diluted $ 0.43 $ 0.98

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Past Due Financing Receivables	The following table presents the outstanding balance of trade accounts receivable that are less than 30 and 60 days past due, in each case, as a percentage of total trade accounts receivable: Delinquency Status March 31, 2019 December 31, 2018 29 days or less past due 96 % 95 % 59 days or less past due 98 % 98 %
Changes in Reserves for Credit Losses Related to Accounts Receivable	The following table presents changes in the accounts receivable allowances: Three Months Ended March 31, (In thousands) 2019 2018 Balance, beginning of year $ 46,948 $ 33,387 Provision for credit losses 17,791 14,226 Charges to other accounts 1 4,533 4,442 Charge-offs (24,800 ) (19,221 ) Recoveries of amounts previously charged-off 2,215 1,926 Currency translation 55 99 Balance, end of period $ 46,742 $ 34,859 1 The Company earns revenue by assessing monthly finance fees on accounts with overdue balances. These fees are recognized as revenue at the time the fees are assessed. The finance fee is calculated using the greater of a minimum charge or a stated late fee rate multiplied by the outstanding balance that is subject to a late fee charge. On occasion, these fees are waived to maintain relationship goodwill. Charges to other accounts represents the offset against the late fee revenue recognized when the Company establishes a reserve for such waived amounts.

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Reconciliation of Income and Share Data Used in Basic and Diluted Earnings Per Share Computations	The following table summarizes net income attributable to shareholders and reconciles basic and diluted shares outstanding used in the earnings per share computations: Three Months Ended March 31, (In thousands) 2019 2018 Net income attributable to shareholders $ 16,134 $ 51,970 Weighted average common shares outstanding – Basic 43,220 43,049 Dilutive impact of share-based compensation awards 352 401 Weighted average common shares outstanding – Diluted 43,572 43,450

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	The following table presents the notional amounts, fixed interest rates and maturities of the interest rate swap agreements entered into during the three months ended March 31, 2019 : Tranche A Tranche B Tranche C Notional amount at inception (in thousands) $150,000 $100,000 $200,000 Maturity date 3/12/2022 3/12/2022 3/12/2023 Fixed interest rate 2.41750% 2.42500% 2.41325%
Location and Amounts of Derivative Gains and Losses in Condensed Consolidated Statements of Income	The following table presents information on the location and amounts of interest rate swap gains and losses: (In thousands) Three Months Ended March 31, Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income Statement 2019 2018 Interest rate swap agreements – unrealized portion Net unrealized (loss) gain on financial instruments $ (12,209 ) $ 13,508 Interest rate swap agreements – realized portion Financing interest income $ 2,116 $ 313

Deposits (Tables)

Deposits (Tables)	3 Months Ended
	Mar. 31, 2019
Banking and Thrift [Abstract]
Schedule of Deposits	The following table presents the composition of deposits: (In thousands) March 31, 2019 December 31, 2018 Interest-bearing brokered money market deposits $ 238,940 $ 283,790 Customer deposits 128,402 138,072 Certificates of deposit with maturities within 1 year (a) 467,996 505,582 Short-term deposits 835,338 927,444 Certificates of deposit with maturities greater than 1 year and less than 5 years (a) 300,349 345,231 Total deposits $ 1,135,687 $ 1,272,675 Weighted average cost of funds on certificates of deposit outstanding 2.40 % 2.36 % Weighted average cost of interest-bearing brokered money market deposits 2.55 % 2.49 % (a) Certificates of deposit are classified as short-term or long-term within our unaudited condensed consolidated balance sheets based on maturity date.

Financing and Other Debt (Table

Financing and Other Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Outstanding Debt	The following table summarizes the Company’s total outstanding debt: (In thousands) March 31, 2019 December 31, 2018 Revolving line-of-credit facility under 2016 Credit Agreement (a) $ 169,206 $ — Term loans under 2016 Credit Agreement (a) 2,279,213 1,745,084 Notes outstanding (a) 400,000 400,000 Securitized debt 105,932 106,872 Participation debt 55,677 114,849 Borrowed federal funds 591 — WEX Latin America debt 17,052 16,242 Total gross debt $ 3,027,671 $ 2,383,047 Current portion of gross debt $ 192,736 $ 223,241 Less: Unamortized debt issuance costs (8,379 ) (6,724 ) Short-term debt, net $ 184,357 $ 216,517 Long-term gross debt $ 2,834,935 $ 2,159,806 Less: Unamortized debt issuance costs (25,574 ) (25,883 ) Long-term debt, net $ 2,809,361 $ 2,133,923 Supplemental information under 2016 Credit Agreement: Letters of credit (b) $ 53,534 $ 53,514 Borrowing capacity on revolving credit facility (c) $ 547,260 $ 666,486 (a) See Note 11, Fair Value, for more information regarding the Company’s 2016 Credit Agreement and Notes. (b) Collateral for lease agreements, virtual card and fuel payment processing activity at the Company’s foreign subsidiaries. (c) Contingent on maintaining compliance with the financial covenants as defined in the Company’s 2016 Credit Agreement
Schedule of Amounts Outstanding Under Participation Debt Agreements in Place	The following table provides the amounts outstanding under the participation debt agreements in place: March 31, 2019 December 31, 2018 (In thousands) Amounts Outstanding Remaining Funding Capacity Amounts Outstanding Remaining Funding Capacity Short-term debt, net (a) $ 5,677 $ 124,323 $ 64,849 $ 65,151 Long-term debt, net (b) $ 50,000 $ — $ 50,000 $ — Average interest rate 4.85 % 4.30 % (a) Amounts outstanding under agreements terminating on June 30, 2019 and on demand. (b) Amounts outstanding under an agreement terminating on August 31, 2020.

Fair Value Fair Value (Tables)

Fair Value Fair Value (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value	The following table presents the Company’s financial instruments that are measured at fair value: (In thousands) Fair Value Hierarchy March 31, 2019 December 31, 2018 Financial Assets: Money market funds (a) 1 $ 5,991 $ 71,228 Investment securities Municipal bonds 2 $ 334 $ 404 Asset-backed securities 2 271 279 Mortgage-backed securities 2 268 260 Fixed-income mutual fund 1 23,899 23,463 Total investment securities $ 24,772 $ 24,406 Executive deferred compensation plan trust (b) 1 $ 7,585 $ 6,398 Interest rate swaps (c) 2 $ 10,805 $ 17,994 Liabilities Interest rate swaps (d) 2 $ 5,020 $ — (a) The fair value is recorded in cash and cash equivalents. (b) The fair value is recorded in prepaid expenses and other current assets and other assets based on the timing of payment obligations. (c) The fair value is recorded in prepaid expenses and other current assets or other assets depending on the timing of expected discounted cash flows. (d) The fair value is recorded in other current liabilities or other liabilities depending on the timing of expected discounted cash flows.

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interest (Tables)	3 Months Ended
	Mar. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interest	The following table presents the changes in the Company’s redeemable non-controlling interest: (In thousands) Three months ended March 31, 2019 Balance, beginning of period $ — Acquisition of Discovery Benefits at fair value 25,757 Establishing redeemable non-controlling interest for WEX Health at carrying value 32,843 Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value 41,400 Net loss attributable to redeemable non-controlling interest (7 ) Balance, end of period $ 99,993

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Supplemental Balance Sheet Information Related to Leases	The following table presents supplemental balance sheet information related to our leases: (In thousands) Balance Sheet Location March 31, 2019 Assets Operating lease ROU assets Other assets $ 80,806 Liabilities Current operating lease liabilities Other current liabilities 12,135 Non-current operating lease liabilities Other liabilities 80,320 Total lease liabilities $ 92,455
Schedule of Lease Term and Discount Rate	The following table presents supplemental cash flow and other information related to our leases: (In thousands) March 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 4,075 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 14,646 The following table presents the weighted average remaining lease term and discount rate: Operating leases March 31, 2019 Weighted average remaining term (in years) 8.7 Weighted average discount rate 4.6 %
Schedule of Maturities of Lease Liabilities	The following table presents the maturities of our lease liabilities: (In thousands) March 31, 2019 Remaining 2019 $ 12,070 2020 15,275 2021 14,810 2022 13,420 2023 11,238 2024 and thereafter 47,688 Total lease payments $ 114,501 Less: Imputed interest 22,046 Total lease obligations $ 92,455 Less: Current portion of lease obligations 12,135 Long-term lease obligations $ 80,320

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Assumptions Used	The table below presents the weighted average fair value of service-based stock options by year of grant and the assumptions used in estimating those fair values: 2019 2018 Weighted average fair value $ 58.28 $ 51.27 Weighted average expected life (in years) 6.0 6.0 Weighted average exercise price $ 184.81 $ 158.23 Expected stock price volatility 27.21 % 27.35 % Risk-free interest rate 2.37 % 2.69 %

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of Reportable Segment Results	The following tables present the Company’s reportable segment revenues: Three Months Ended March 31, 2019 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Revenues Payment processing revenue $ 107,408 $ 59,998 $ 19,392 $ 186,798 Account servicing revenue 39,239 10,585 37,262 87,086 Finance fee revenue 45,864 357 152 46,373 Other revenue 40,271 10,708 10,640 61,619 Total revenues $ 232,782 $ 81,648 $ 67,446 $ 381,876 Interest income $ 2,221 $ 377 $ 159 $ 2,757 Three Months Ended March 31, 2018 (In thousands) Fleet Solutions Travel and Corporate Solutions Health and Employee Benefit Solutions Total Revenues Payment processing revenue $ 106,978 $ 44,777 $ 16,699 $ 168,454 Account servicing revenue 42,210 9,469 27,025 78,704 Finance fee revenue 43,604 259 5,018 48,881 Other revenue 37,573 12,274 8,142 57,989 Total revenues $ 230,365 $ 66,779 $ 56,884 $ 354,028 Interest income $ 995 $ 421 $ 5,967 $ 7,383
Reconciliation of Adjusted Net Income to Income Before Income Taxes	The following table reconciles segment adjusted operating income to income before income taxes: Three Months Ended March 31, (In thousands) 2019 2018 Segment adjusted operating income Fleet Solutions $ 92,975 $ 107,973 Travel and Corporate Solutions 34,387 25,249 Health and Employee Benefit Solutions 19,780 18,071 Total segment adjusted operating income $ 147,142 $ 151,293 Reconciliation: Total segment adjusted operating income $ 147,142 $ 151,293 Less: Unallocated corporate expenses 16,942 13,920 Acquisition-related intangible amortization 33,888 35,236 Other acquisition and divestiture related items 9,780 637 Debt restructuring costs 4,400 3,015 Stock-based compensation 10,442 8,955 Restructuring and other costs 2,755 5,671 Operating income 68,935 83,859 Financing interest expense (31,112 ) (27,337 ) Net foreign currency (loss) gain (3,885 ) 390 Net unrealized (loss) gain on financial instruments (11,912 ) 13,508 Income before income taxes $ 22,026 $ 70,420

Supplementary Regulatory Capi_2

Supplementary Regulatory Capital Disclosure (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The following table presents WEX Bank’s actual and regulatory minimum capital amounts and ratios: (In thousands) Actual Amount Ratio Minimum for Capital Adequacy Purposes Amount Ratio Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio March 31, 2019 Total Capital to risk-weighted assets $ 317,780 12.01 % $ 211,640 8.0 % $ 264,550 10.0 % Tier 1 Capital to average assets $ 302,413 10.92 % $ 110,746 4.0 % $ 138,432 5.0 % Common equity to risk-weighted assets $ 302,413 11.43 % $ 119,048 4.5 % $ 171,958 6.5 % Tier 1 Capital to risk-weighted assets $ 302,413 11.43 % $ 158,730 6.0 % $ 211,640 8.0 % December 31, 2018 Total Capital to risk-weighted assets $ 323,178 12.82 % $ 201,749 8.0 % $ 252,186 10.0 % Tier 1 Capital to average assets $ 305,734 10.88 % $ 112,401 4.0 % $ 140,501 5.0 % Common equity to risk-weighted assets $ 305,734 12.12 % $ 113,484 4.5 % $ 163,921 6.5 % Tier 1 Capital to risk-weighted assets $ 305,734 12.12 % $ 151,312 6.0 % $ 201,749 8.0 %

Basis of Presentation (Details)

Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues	$ 381,876	$ 354,028
Provision for credit losses	17,791	14,226
Operating income	68,935	83,859
Income taxes	5,818	17,749
Net income	$ 16,208	52,671
Net income attributable to shareholders		$ 51,970
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)	$ 0.37	$ 1.21
Diluted (in dollars per share)	$ 0.37	$ 1.20
Net cash provided by operating activities	$ 70,110	$ 87,806
Effect of exchange rates on cash, cash equivalents and restricted cash		(587)
Cash, cash equivalents and restricted cash, beginning of period	526,078	399,885	$ 555,031	$ 522,385
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		354,829
Provision for credit losses		13,990
Operating income		78,362
Income taxes		15,589
Net income		49,334
Net income attributable to shareholders		$ 48,633
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)		$ 1.13
Diluted (in dollars per share)		$ 1.12
Net cash provided by operating activities		$ 85,243
Effect of exchange rates on cash, cash equivalents and restricted cash		(2,577)
Cash, cash equivalents and restricted cash, beginning of period				526,938
Brazil Adjustments | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		(801)
Provision for credit losses		236
Operating income		5,497
Income taxes		2,343
Net income		3,154
Net income attributable to shareholders		$ 3,154
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)		$ 0.08
Diluted (in dollars per share)		$ 0.08
Net cash provided by operating activities		$ 0
Effect of exchange rates on cash, cash equivalents and restricted cash		0
Cash, cash equivalents and restricted cash, beginning of period				0
Other Immaterial Adjustments | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenues		0
Provision for credit losses		0
Operating income		0
Income taxes		(183)
Net income		183
Net income attributable to shareholders		$ 183
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)		$ 0
Diluted (in dollars per share)		$ 0
Net cash provided by operating activities		$ 2,563
Effect of exchange rates on cash, cash equivalents and restricted cash		1,990
Cash, cash equivalents and restricted cash, beginning of period				$ (4,553)
Payment processing revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Processing costs	$ 91,119	73,106
Payment processing revenue | Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Processing costs		79,640
Payment processing revenue | Brazil Adjustments | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Processing costs		(6,534)
Payment processing revenue | Other Immaterial Adjustments | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Processing costs		$ 0

Revenue - Summary of Disaggrega

Revenue - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	$ 266,312	$ 239,715
Total revenues	381,876	354,028
Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	131,194	132,486
Total revenues	232,782	230,365
Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	71,688	55,363
Total revenues	81,648	66,779
Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	63,430	51,866
Total revenues	67,446	56,884
Payment processing revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	186,798	168,454
Payment processing revenue | Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	107,408	106,978
Payment processing revenue | Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	59,998	44,777
Payment processing revenue | Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	19,392	16,699
Account servicing revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	54,647	44,960
Total revenues	32,439	33,744
Account servicing revenue | Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	6,800	8,466
Total revenues	32,439	33,744
Account servicing revenue | Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	10,585	9,469
Total revenues	0	0
Account servicing revenue | Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	37,262	27,025
Total revenues	0	0
Finance fee revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	46,373	48,881
Finance fee revenue | Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	45,864	43,604
Finance fee revenue | Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	357	259
Finance fee revenue | Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	152	5,018
Other revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	24,867	26,301
Total revenues	36,752	31,688
Other revenue | Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	16,986	17,042
Total revenues	23,285	20,531
Other revenue | Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	1,105	1,117
Total revenues	9,603	11,157
Other revenue | Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Topic 606 revenues	6,776	8,142
Total revenues	3,864	0
Total non-Topic 606 revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	115,564	114,313
Total non-Topic 606 revenues | Fleet Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	101,588	97,879
Total non-Topic 606 revenues | Travel and corporate solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	9,960	11,416
Total non-Topic 606 revenues | Health and Employee Benefit Solutions
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	$ 4,016	$ 5,018

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Variable consideration	$ 198.7	$ 198.5
Waived fees	4.5	$ 4.4
Revenue recognized related to contract liabilities	$ 2.8

Revenue - Contract Assets and L

Revenue - Contract Assets and Liabilities From Contracts with Customers (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract assets	$ 5,576	$ 3,819
Short-term deposits	835,338	927,444
Accounts receivable, net
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract assets	41,092	32,949
Other assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract assets	20,280	19,232
Other current liabilities
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Short-term deposits	$ 6,594	$ 7,612

Revenue - Remaining Performance

Revenue - Remaining Performance Obligation (Details) $ in Thousands	Mar. 31, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 57,431
Performance obligations expected to be satisfied, expected timing	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 45,776
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	11,655
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 40,800
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 40,285
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	515
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 23,227
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 23,227
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 12,313
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 12,313
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 3,753
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 3,753
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 639
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 639
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 138,163
Performance obligations expected to be satisfied, expected timing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Monthly Fees
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 125,993
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Professional Services
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied	$ 12,170

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ in Thousands, € in Millions	Mar. 05, 2019USD ($)	Feb. 14, 2019USD ($)	Jan. 24, 2019USD ($)	Mar. 31, 2019USD ($)	Oct. 31, 2018USD ($)	Mar. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2019EUR (€)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Payment for trade accounts receivable portfolio					$ 223,400
Premium in excess of receivables' estimated fair value					162,800
Payment in escrow for carrying value of accounts receivable					$ 38,900
Goodwill				$ 2,331,110		$ 2,331,110			$ 2,331,110	$ 1,832,129
Discovery Benefits
Business Acquisition [Line Items]
Consideration transferred	$ 525,600
Deferred cash consideration	50,000								50,000
Fair value of equity interests acquired	$ 100,000
Revenue from acquiree since acquisition				8,600
Net loss from acquiree since acquisition				(1,100)
Goodwill				272,605		272,605			272,605
Accounts receivable acquired				10,367		10,367			10,367
Pavestone Capital
Business Acquisition [Line Items]
Consideration transferred		$ 28,100
Goodwill		12,800
Accounts receivable acquired		$ 14,600
Noventis
Business Acquisition [Line Items]
Consideration transferred			$ 343,100
Deferred cash consideration									15,594
Amount of accelerated vesting of options									5,600
Revenue from acquiree since acquisition						9,200
Net loss from acquiree since acquisition						1,800
Goodwill				213,059		213,059			213,059
Accounts receivable acquired				$ 23,002		$ 23,002			$ 23,002
Scenario, Forecast | Go Fuel Card
Business Acquisition [Line Items]
Consideration transferred							$ 265,500	€ 235
Discovery Benefits
Business Acquisition [Line Items]
Ownership percentage by noncontrolling interest	4.90%

Acquisitions - Schedules of Ass

Acquisitions - Schedules of Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	Mar. 05, 2019	Mar. 31, 2019	Mar. 31, 2018	Feb. 14, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Cash consideration, net of cash and restricted cash acquired of $125,865		$ 568,426	$ 0
Less:
Recorded goodwill		$ 2,331,110			$ 1,832,129
Weighted average life (in years)		7 years
Discovery Benefits
Business Acquisition [Line Items]
Cash consideration, net of cash and restricted cash acquired of $125,865		$ 249,781
Fair value of redeemable non-controlling interest		100,000
Deferred cash consideration	$ 50,000	50,000
Restricted cash		125,865
Less:
Accounts receivable		10,367
Other assets		13,589
Accrued expenses		(7,399)
Restricted cash payable		(125,346)
Deferred income taxes		(22,200)
Other liabilities		(10,015)
Accounts payable		(3,024)
Recorded goodwill		272,605
Pavestone Capital
Less:
Accounts receivable				$ 14,600
Recorded goodwill				$ 12,800
Noventis
Business Acquisition [Line Items]
Cash consideration, net of cash and restricted cash acquired of $125,865		275,970
Deferred cash consideration		15,594
Total consideration		291,564
Less:
Accounts receivable		23,002
Property and equipment		549
Deferred income taxes		(24,121)
Other liabilities		(2,518)
Other assets		2,487
Accounts payable		(36,794)
Recorded goodwill		$ 213,059
Weighted average life (in years)		7 years 7 months 6 days
Customer relationships
Less:
Weighted average life (in years)		7 years 3 months 18 days
Customer relationships | Discovery Benefits
Business Acquisition [Line Items]
Total consideration		$ 399,781
Less:
Property and equipment		4,904
Intangible assets		213,600
Customer relationships | Noventis
Less:
Intangible assets		$ 100,900
Weighted average life (in years)		8 years 3 months 18 days
Developed technologies
Less:
Weighted average life (in years)		5 years 4 months 24 days
Developed technologies | Discovery Benefits
Less:
Intangible assets		$ 38,900
Developed technologies | Noventis
Less:
Intangible assets		$ 15,000
Weighted average life (in years)		2 years 10 months 24 days
Trademarks and trade names
Less:
Weighted average life (in years)		7 years 3 months 18 days
Trademarks and trade names | Discovery Benefits
Less:
Intangible assets		$ 13,800

Acquisitions - Schedule of Pro

Acquisitions - Schedule of Pro Forma Information (Details) - Discovery Benefits and Noventis - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total revenues	$ 400,982	$ 381,826
Net income attributable to shareholders	$ 18,810	$ 42,487
Net income attributable to WEX Inc. per share:
Basic (in dollars per share)	$ 0.44	$ 0.99
Diluted (in dollars per share)	$ 0.43	$ 0.98

Accounts Receivable - Additiona

Accounts Receivable - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Trade receivable payments terms (30 days or less)	30 days
Threshold period past due for write-off of trade accounts receivable	150 days
Revolving line-of-credit facility under 2016 Credit Agreement
Concentration Risk [Line Items]
Receivables with revolving credit balances	$ 43	$ 18.9
29 days or less past due | Credit Concentration Risk | Accounts receivable, net
Concentration Risk [Line Items]
Concentration risk, percentage	96.00%	95.00%
59 days or less past due | Credit Concentration Risk | Accounts receivable, net
Concentration Risk [Line Items]
Concentration risk, percentage	98.00%	98.00%

Accounts Receivable - Changes i

Accounts Receivable - Changes in Reserves for Accounts Receivable (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of year	$ 46,948	$ 33,387
Provision for credit losses	17,791	14,226
Charges to other accounts	4,533	4,442
Charge-offs	(24,800)	(19,221)
Recoveries of amounts previously charged-off	2,215	1,926
Currency translation	55	99
Balance, end of period	$ 46,742	$ 34,859

Earnings per Share - Summary of

Earnings per Share - Summary of Net Earning Attributable to Shareholders and Reconciliation of Basic and Diluted Shares (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income attributable to shareholders	$ 16,134	$ 51,970
Weighted average common shares outstanding – Basic (in shares)	43,220	43,049
Dilutive impact of share-based compensation awards (in shares)	352	401
Weighted average common shares outstanding – Diluted (in shares)	43,572	43,450

Earnings per Share - Stock Opti

Earnings per Share - Stock Options and Restricted Stock Units (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) $ in Billions	Mar. 31, 2019USD ($)	Mar. 12, 2019contract	Dec. 31, 2018USD ($)contract
Interest rate swaps
Derivative [Line Items]
Number of interest rate swap contracts entered into | contract		3	4
Borrowings under derivative agreements	$ 1.5		$ 1
Interest rate swaps | Minimum
Derivative [Line Items]
Fixed rate variable interest			1.108%
Interest rate swaps | Maximum
Derivative [Line Items]
Fixed rate variable interest			2.212%
2016 Credit Agreement
Derivative [Line Items]
Lines of credit outstanding	$ 2.4

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Interest Rate Swaps (Details) - Derivatives Not Designated as Hedging Instruments	Mar. 31, 2019USD ($)
Tranche A
Derivative [Line Items]
Notional amount at inception (in thousands)	$ 150,000,000
Fixed interest rate	2.4175%
Tranche B
Derivative [Line Items]
Notional amount at inception (in thousands)	$ 100,000,000
Fixed interest rate	2.425%
Tranche C
Derivative [Line Items]
Notional amount at inception (in thousands)	$ 200,000,000
Fixed interest rate	2.41325%

Derivative Instruments - Locati

Derivative Instruments - Location and Amounts of Interest Rate Swap Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains on financial instruments	$ (11,912)	$ 13,508
Derivatives Not Designated as Hedging Instruments | Net unrealized gain on interest rate swap agreements | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains on financial instruments	(12,209)	13,508
Derivatives Not Designated as Hedging Instruments | Financing interest income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gains on financial instruments	$ 2,116	$ 313

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Required reserve based on the outstanding customer deposits	$ 11,200,000	$ 11,100,000
Maximum money market and demand deposit accounts purchasable	125,000,000
Outstanding balance of ICS purchases	$ 0	$ 0
Minimum
Debt Instrument [Line Items]
Certificate of deposits maturities period	1 year
Certificate of deposits, fixed interest rates range (as a percent)	1.30%
Maximum
Debt Instrument [Line Items]
Certificate of deposits maturities period	5 years
Certificate of deposits, fixed interest rates range (as a percent)	3.52%

Financing and Other Debt - Sche

Financing and Other Debt - Schedule of Debt (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,027,671,000	$ 2,383,047,000
Current portion of gross debt	192,736,000	223,241,000
Less: Unamortized debt issuance costs	(8,379,000)	(6,724,000)
Short-term debt, net	184,357,000	216,517,000
Long-term gross debt	2,834,935,000	2,159,806,000
Less: Unamortized debt issuance costs	(25,574,000)	(25,883,000)
Long-term debt, net	2,809,361,000	$ 2,133,923,000
2016 Credit Agreement
Supplemental information under 2016 Credit Agreement:
Letters of credit	$ 2,400,000,000
Weighted average annual interest rate, percent	4.60%	4.70%
Loan Participations and Assignments
Debt Instrument [Line Items]
Funding capacity of participation debt	$ 124,323,000	$ 65,151,000
Long-term debt, gross	$ 55,677,000	$ 114,849,000
Supplemental information under 2016 Credit Agreement:
Weighted average annual interest rate, percent	4.85%	4.30%
Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Supplemental information under 2016 Credit Agreement:
Maximum borrowing capacity	$ 547,260,357.349	$ 666,486,000
Secured debt
Debt Instrument [Line Items]
Long-term debt, gross	105,932,000	106,872,000
Line of Credit
Debt Instrument [Line Items]
Long-term debt, gross	591,000	0
Line of Credit | Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Debt Instrument [Line Items]
Long-term debt, gross	169,206,000	0
Line of Credit | Secured debt | 2016 Credit Agreement
Debt Instrument [Line Items]
Long-term debt, gross	2,279,213,000	1,745,084,000
Notes payable | Senior Notes
Debt Instrument [Line Items]
Long-term debt, gross	400,000,000	400,000,000
Letter of Credit | Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Supplemental information under 2016 Credit Agreement:
Letters of credit	53,534,000	53,514,000
Long-term Debt | Loan Participations and Assignments
Debt Instrument [Line Items]
Debt balance	50,000,000	50,000,000
Short-term Debt | Loan Participations and Assignments
Debt Instrument [Line Items]
Debt balance	$ 5,677,000	$ 64,849,000

Deposits - Schedule of Composi

Deposits - Schedule of Composition of Deposits (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Interest-bearing brokered money market deposits	$ 238,940	$ 283,790
Customer deposits	128,402	138,072
Certificates of deposit with maturities within 1 year	467,996	505,582
Short-term deposits	835,338	927,444
Certificates of deposit with maturities greater than 1 year and less than 5 years	300,349	345,231
Total deposits	$ 1,135,687	$ 1,272,675
Weighted average cost of funds on certificates of deposit outstanding (as a percent)	2.40%	2.36%
Weighted average cost of interest-bearing money market deposits (as a percent)	2.55%	2.49%

Financing and Other Debt - Addi

Financing and Other Debt - Additional Information (Details) - USD ($)	Apr. 07, 2016	Mar. 31, 2019	Dec. 31, 2018	Mar. 05, 2019	Jan. 18, 2019
Debt Instrument [Line Items]
General and administrative costs incurred		$ 4,400,000
Debt issuance costs					$ 3,400,000
Long-term debt		$ 3,027,671,000	$ 2,383,047,000
Interest rate during period, percent		2.64%
2016 Credit Agreement
Debt Instrument [Line Items]
Weighted average annual interest rate, percent		4.60%	4.70%
Delayed Draw Commitment
Debt Instrument [Line Items]
Current borrowing capacity					275,000,000
Australian Securitization Facility
Debt Instrument [Line Items]
Percentage used as collateral		85.00%
Interest rate during period, percent		2.90%	2.89%
Short-term debt, net		$ 78,700,000	$ 87,000,000
European Securitization Facility
Debt Instrument [Line Items]
Interest rate during period, percent		0.87%	0.98%
Debt instrument, term	5 years
Securitized debt		$ 26,400,000	$ 18,000,000
Loan Participations and Assignments
Debt Instrument [Line Items]
Weighted average annual interest rate, percent		4.85%	4.30%
Long-term debt		$ 55,677,000	$ 114,849,000
Funding capacity of participation debt		$ 124,323,000	65,151,000
Loan Participations and Assignments | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Margin on variable rate, percent		2.25%
Credit Facility Term Loans | 2016 Credit Agreement Tranche A
Debt Instrument [Line Items]
Current borrowing capacity			480,000,000	$ 250,000,000	723,700,000
Incremental revolving commitments					300,000,000
Mandatory quarterly payments		$ 12,500,000
Credit Facility Term Loans | Revolving line-of-credit facility under 2016 Credit Agreement
Debt Instrument [Line Items]
Current borrowing capacity				$ 50,000,000
Credit Facility Term Loans | 2016 Credit Agreement Tranche B
Debt Instrument [Line Items]
Current borrowing capacity			1,335,000,000
Mandatory quarterly payments		$ 3,400,000
Credit Facility Term Loans | 2016 Credit Agreement Tranche B | Base Rate
Debt Instrument [Line Items]
Margin on variable rate, percent		2.25%
Credit Facility Term Loans | 2016 Credit Agreement Tranche B | Eurocurrency Rate
Debt Instrument [Line Items]
Margin on variable rate, percent		1.25%
Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Debt Instrument [Line Items]
Current borrowing capacity			720,000,000
Incremental revolving commitments					$ 25,000,000
Line of Credit
Debt Instrument [Line Items]
Long-term debt		$ 591,000	0
WEX Latin America
Debt Instrument [Line Items]
Long-term debt		$ 17,052,000	$ 16,242,000
Interest rate during period, percent		24.74%	23.59%
Short-term debt		$ 17,100,000	$ 16,200,000
Letter of Credit | Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Debt Instrument [Line Items]
Current borrowing capacity			250,000,000
Swingline Loan | Revolving line-of-credit facility under 2016 Credit Agreement | 2016 Credit Agreement
Debt Instrument [Line Items]
Current borrowing capacity			20,000,000
Senior Notes | Notes payable
Debt Instrument [Line Items]
Senior notes		400,000,000	400,000,000
Long-term debt		$ 400,000,000	$ 400,000,000
Interest rate, stated percentage		4.75%	4.75%
Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 327,409,466	$ 309,000,000
Short-term Debt | Loan Participations and Assignments
Debt Instrument [Line Items]
Debt balance		5,677,000	64,849,000
Long-term Debt | Loan Participations and Assignments
Debt Instrument [Line Items]
Debt balance		$ 50,000,000	$ 50,000,000

Off-Balance Sheet Arrangements

Off-Balance Sheet Arrangements (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of factoring receivables	$ 2,000,000,000
Loss on sale of factoring receivables	600,000
Operating interest	2,757,000	$ 7,383,000
WEX Europe Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of factoring receivables	150,000,000	170,200,000
Loss on sale of factoring receivables	800,000	$ 1,100,000
WEX Latin America
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loss on sale of factoring receivables	(3,700,000)
WEX Latin America Securitization Facility | WEX Latin America
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of factoring receivables	20,700,000
Equity contributions to investment fund	$ 0
Operating interest			$ 2,100,000

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities Measured at Fair Value and Related Hierarchy Levels (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financial Assets:
Total investment securities	$ 24,772	$ 24,406
Level 1
Financial Assets:
Executive deferred compensation plan trust	7,585	6,398
Level 2 | Interest rate swaps
Financial Assets:
Derivative asset	10,805	17,994
Liabilities
Interest rate swaps	5,020	0
Money Market Funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	5,991	71,228
Municipal bonds | Level 2
Financial Assets:
Total investment securities	334	404
Asset-backed securities | Level 2
Financial Assets:
Total investment securities	271	279
Mortgage-backed securities | Level 2
Financial Assets:
Total investment securities	268	260
Fixed-income mutual fund | Level 1
Financial Assets:
Total investment securities	$ 23,899	$ 23,463

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Senior Notes | Estimate of Fair Value Measurement | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	$ 399	$ 392

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interest - Narrative (Details) - USD ($) $ in Thousands	Mar. 05, 2019	Mar. 31, 2019
Noncontrolling Interest [Line Items]
Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value		$ 41,400
Additional Paid-in Capital
Noncontrolling Interest [Line Items]
Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value		$ (41,400)
Discovery Benefits
Noncontrolling Interest [Line Items]
Ownership percentage by noncontrolling interest	4.90%
Discovery Benefits | Additional Paid-in Capital
Noncontrolling Interest [Line Items]
Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value	$ 41,400
Discovery Benefits | Non–Controlling Interest
Noncontrolling Interest [Line Items]
Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value	$ 41,400
Minimum | Discovery Benefits
Noncontrolling Interest [Line Items]
Call rights, exercise period		5 years
Maximum | Discovery Benefits
Noncontrolling Interest [Line Items]
Call rights, exercise period		7 years

Redeemable Non-Controlling In_4

Redeemable Non-Controlling Interest - Schedule of Redeemable Non-Controlling Interest (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, beginning of period	$ 0
Establishing redeemable non-controlling interest for WEX Health at carrying value	25,757
Establishing redeemable non-controlling interest for WEX Health at carrying value	32,843
Adjustment to redeemable non-controlling interest to reflect WEX Health at fair value	41,400
Net loss attributable to redeemable non-controlling interest	(7)
Balance, end of period	$ 99,993

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective tax rate	26.40%	25.20%
Undistributed earnings of certain foreign subsidiaries	$ 77		$ 64.9

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information (Details) $ in Thousands	Mar. 31, 2019USD ($)
Assets
Operating lease ROU assets	$ 80,806
Liabilities
Current operating lease liabilities	12,135
Non-current operating lease liabilities	80,320
Total lease liabilities	$ 92,455

Leases - Schedule of Lease Term

Leases - Schedule of Lease Term and Discount Rate (Details)	Mar. 31, 2019
Leases [Abstract]
Weighted-average remaining operating lease term (in years)	8 years 8 months 12 days
Weighted-average discount rate (as a percent)	4.60%

Leases - Maturities of Lease Pa

Leases - Maturities of Lease Payments (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
Remaining 2019	$ 12,070
2020	15,275
2021	14,810
2022	13,420
2023	11,238
2024 and thereafter	47,688
Total lease payments	114,501
Less: Imputed interest	22,046
Total lease liabilities	92,455
Less: Current portion of lease obligation	12,135
Long-term lease obligations	$ 80,320

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Additional lease not yet commenced, term (in years)	14 years
Additional lease not yet commenced	$ 30
Operating lease cost	$ 4

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 4,075
Right-of-use assets obtained in exchange for lease liabilities:	$ 14,646

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Fair value of units awarded	$ 38.1	$ 27.4

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Stock Options (Details) - Stock Options - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value (in dollars per share)	$ 58.28	$ 51.27
Weighted average expected life (in years)	6 years	6 years
Weighted average exercise price (in dollars per share)	$ 184.81	$ 158.23
Expected stock price volatility (as a percent)	27.21%	27.35%
Weighted average risk–free rate	2.37%	2.69%

Restructuring Activities - Addi

Restructuring Activities - Additional Information (Details) $ in Millions	Mar. 31, 2019USD ($)
Restructuring and Related Activities [Abstract]
Restructuring charges incurred to date	$ 24.8

Segment Information - Additiona

Segment Information - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information - Revenue b

Segment Information - Revenue by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Payment processing revenue	$ 266,312	$ 239,715
Account servicing revenue	87,086	78,704
Finance fee revenue	46,373	48,881
Other revenue	61,619	57,989
Total revenues	381,876	354,028
Interest income	2,757	7,383
Fleet Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	131,194	132,486
Account servicing revenue	39,239	42,210
Finance fee revenue		43,604
Other revenue	40,271	37,573
Total revenues	232,782	230,365
Interest income	2,221	995
Travel and Corporate Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	71,688	55,363
Account servicing revenue		9,469
Finance fee revenue		259
Other revenue	10,708	12,274
Total revenues	81,648	66,779
Interest income	377	421
Health and Employee Benefit Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	63,430	51,866
Account servicing revenue		27,025
Finance fee revenue		5,018
Other revenue	10,640	8,142
Total revenues	67,446	56,884
Interest income	159	5,967
Payment processing revenue
Segment Reporting Information [Line Items]
Payment processing revenue	186,798	168,454
Payment processing revenue | Fleet Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	107,408	106,978
Payment processing revenue | Travel and Corporate Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	59,998	44,777
Payment processing revenue | Health and Employee Benefit Solutions
Segment Reporting Information [Line Items]
Payment processing revenue	$ 19,392	$ 16,699

Segment Information - Reconcili

Segment Information - Reconciliation of Adjusted Operating Income to Income Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Adjusted operating income	$ 147,142	$ 151,293
Stock-based compensation	9,703	8,955
Operating income	68,935	83,859
Financing interest expense	(31,112)	(27,337)
Net foreign currency (loss) gain	(3,885)	390
Net unrealized gains on financial instruments	(11,912)	13,508
Income before income taxes	22,026	70,420
Fleet Solutions
Segment Reporting Information [Line Items]
Adjusted operating income	92,975	107,973
Travel and corporate solutions
Segment Reporting Information [Line Items]
Adjusted operating income	34,387	25,249
Health and Employee Benefit Solutions
Segment Reporting Information [Line Items]
Adjusted operating income	19,780	18,071
Segment reconciling items
Segment Reporting Information [Line Items]
Unallocated corporate expenses	16,942	13,920
Acquisition-related intangible amortization	33,888	35,236
Other acquisition and divestiture related items	9,780	637
Debt restructuring costs	4,400	3,015
Stock-based compensation	10,442	8,955
Restructuring and other costs	$ 2,755	$ 5,671

Supplementary Regulatory Capi_3

Supplementary Regulatory Capital Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Total Capital to risk-weighted assets, Actual Amount	$ 317,780	$ 323,178
Total Capital to risk-weighted assets, Actual, Ratio	12.01%	12.82%
Total Capital to risk-weighted assets, Minimum for Capital Adequacy Purposes Amount	$ 211,640	$ 201,749
Total Capital to risk-weighted assets, Minimum for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Capital to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 264,550	$ 252,186
Total Capital to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 Capital to average assets, Actual Amount	$ 302,413	$ 305,734
Tier 1 Capital to average assets, Actual, Ratio	10.92%	10.88%
Tier 1 Capital to average assets, Minimum for Capital Adequacy Purposes Amount	$ 110,746	$ 112,401
Tier 1 Capital to average assets, Minimum for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Capital to average assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 138,432	$ 140,501
Tier 1 Capital to average assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provision, Ratio	5.00%	5.00%
Common equity to risk-weighted assets, Actual Amount	$ 302,413	$ 305,734
Common equity to risk-weighted assets, Actual, Ratio	11.43%	12.12%
Common equity to risk-weighted assets, Minimum for Capital Adequacy Purposes Amount	$ 119,048	$ 113,484
Common equity to risk-weighted assets, Minimum for Capital Adequacy Purposes, Ratio	4.50%	4.50%
Common equity to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 171,958	$ 163,921
Common equity to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
Tier 1 Capital to risk-weighted assets, Actual Amount	$ 302,413	$ 305,734
Tier 1 Capital to risk-weighted assets, Actual, Ratio	11.43%	12.12%
Tier 1 Capital to risk-weighted assets, Minimum for Capital Adequacy Purposes Amount	$ 158,730	$ 151,312
Tier 1 Capital to risk-weighted assets, Minimum for Capital Adequacy Purposes, Ratio	6.00%	6.00%
Tier 1 Capital to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 211,640	$ 201,749
Tier 1 capital to risk-weighted assets, Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions Amount, Ratio	8.00%	8.00%

Uncategorized Items - wex-20190

Label	Element	Value
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	$ 1,630,738,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	638,000	[1]
Common Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	$ 473,000
Shares, Issued	us-gaap_SharesIssued	47,352,000
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	$ 1,313,298,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	638,000	[1]
Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	(172,342,000)
Additional Paid-in Capital [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	569,319,000
Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	9,220,000
AOCI Attributable to Parent [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	$ (89,230,000)
[1]	Includes the impact of the Company’s modified retrospective adoption as part of Topic 606.