Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation The accompanying unaudited consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP. We consolidated our wholly-owned subsidiaries and eliminated all significant intercompany balances and transactions. We have also prepared the accompanying unaudited consolidated financial statements in conformity with the instructions to Form 10-Q and Article 10 of Regulation S-X and, consequently, they do not include all of the annual disclosures required by GAAP. Reference is made to our Annual Report on Form 10-K for the year ended December 31, 2017 for additional disclosures, including a summary of our significant accounting policies. There have been no material changes to our significant accounting policies during the nine months ended September 30, 2018, other than the adoption of the accounting pronouncements discussed below. In our opinion, the accompanying unaudited consolidated financial statements contain all adjustments, consisting of normal and recurring items, except as otherwise noted, necessary for the fair presentation of our financial position, results of operations and cash flows for the interim periods presented.
Recent accounting pronouncements	Recent Accounting Pronouncements Recently issued accounting pronouncements not yet adopted In August 2018, the FASB issued ASU No. 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract ("ASU 2018-15"), which amends ASC 350-40 to address implementation costs incurred in a cloud computing arrangement (CCA) that is a service contract. ASU 2018-15 aligns the accounting for costs incurred to implement a CCA that is a service arrangement with the guidance on capitalizing costs associated with developing or obtaining internal-use software. As a result, certain implementation costs incurred by companies under hosting arrangements will be deferred and amortized. ASU 2018-15 is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the impact of the pronouncement on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other ("ASU 2017-04"): Simplifying the Test for Goodwill Impairment, which simplifies the existing two-step guidance for goodwill impairment testing by eliminating the second s tep resulting in a write-down to goodwill equal to the initial amount of impairment determined in step one. The ASU is to be applied prospectively for reporting periods beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed after January 1, 2017. We are currently evaluating the impact of the provisions of ASU 2017-04 on our consolidated financial statements; however, we do not anticipate it will have a material impact upon adoption. Note 2—Summary of Significant Accounting Policies (continued) In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ("ASU 2016-13") that requires financial assets measured at amortized cost be presented at the net amount expected to be collected. Credit losses on available-for-sale debt securities should be recorded through an allowance for credit losses limited by the amount that the fair value is less than amortized cost. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the impact of ASU 2016-13 on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) ("ASU 2016-02") in order to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under previous GAAP. The guidance has been modified through additional technical corrections since its original issuance, including optional transition relief as provided for under ASU No. 2018-11- Leases (Topic 842): Targeted Improvements. ASU 2016-02 requires that a lessee should recognize a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for leases with a term greater than 12 months. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those periods and early adoption is permitted. We are currently assessing the impact of the adoption of this principle on our consolidated financial statements. We have reviewed the requirements under the new standard, and are in the process of quantifying its effect on our consolidated financial statements upon adoption and assessing its impact on our related disclosures or our internal controls over financial reporting. We anticipate adopting this ASU on January 1, 2019 on a prospective basis with a cumulative effect adjustment to retained earnings, if any, upon adoption. Recently adopted accounting pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"), and has been modified through additional technical corrections since its original issuance (collectively ASC 606). ASU 2014-09 supersedes nearly all existing revenue recognition guidance under current GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. The standard defines a five step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under previous GAAP. The standard allows companies to apply either a full retrospective approach, which requires applying the standard to each prior year reporting period presented, or a modified retrospective approach with a cumulative effect adjustment recognized upon adoption. We adopted the provisions of the standard on January 1, 2018 using the modified retrospective approach, which did not result in any cumulative adjustment to opening retained earnings nor did it have a material impact on our consolidated financial statements. The adoption of ASU 2014-09, however, requires expanded disclosures under the new guidance. See Note 3 - Revenues for further information and additional discussion around changes identified to our policies under the new accounting pronouncement. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). ASU 2016-01 revises the classification and measurement of investments in certain equity investments and the presentation of certain fair value changes for certain financial liabilities measured at fair value. ASU 2016-01 requires the change in fair value of many equity investments to be recognized in net income. We adopted the provisions of ASU 2016-01 on January 1, 2018, the result of which did not have any impact upon our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash ("ASU 2016-18"), to require that restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total cash amounts shown on the statement of cash flows. Consequently, transfers between cash and restricted cash will not be presented as a separate line item in the operating, investing or financing sections of the cash flow statement. The amendments should be applied retrospectively to each period presented. We adopted the provisions of ASU 2016-18 on January 1, 2018, the effect of which resulted in an immaterial reclassification in presentation on our statement of cash flows and had no effect on our consolidated financial results. Note 2—Summary of Significant Accounting Policies (continued) In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ("ASU 2018-02"). Under existing U.S. GAAP, the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in accumulated other comprehensive income are adjusted, certain tax effects become stranded in accumulated other comprehensive income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the 2017 Tax Cuts and Jobs Act. The amendments in this ASU also require certain disclosures about stranded tax effects. We adopted the provisions of ASU 2018-02 as of December 31, 2017, the result of which did not have a material impact upon our consolidated financial statements.
Fair value of financial instruments	Short-term Financial Instruments Our short-term financial instruments consist principally of unrestricted and restricted cash and cash equivalents, settlement assets and obligations, and obligations to customers. These financial instruments are short-term in nature, and, accordingly, we believe their carrying amounts approximate their fair values. Under the fair value hierarchy, these instruments are classified as Level 1. Investment Securities The fair values of investment securities have been derived using methodologies referenced in Note 2–Summary of Significant Accounting Policies to the Consolidated Financial Statements of our Annual Report on Form 10-K for the year ended December 31, 2017. Under the fair value hierarchy, our investment securities are classified as Level 2. Loans We determined the fair values of loans by discounting both principal and interest cash flows expected to be collected using a discount rate commensurate with the risk that we believe a market participant would consider in determining fair value. Under the fair value hierarchy, our loans are classified as Level 3. Deposits The fair value of demand and interest checking deposits and savings deposits is the amount payable on demand at the reporting date. We determined the fair value of time deposits by discounting expected future cash flows using market-derived rates based on our market yields on certificates of deposit, by maturity, at the measurement date. Under the fair value hierarchy, our deposits are classified as Level 2. Contingent Consideration The fair value of contingent consideration obligations, such as the earn-outs associated with our acquisitions of TPG and UniRush, are estimated through valuation models designed to estimate the probability of such contingent payments based on various assumptions. Estimated payments are discounted using present value techniques to arrive at an estimated fair value. Our contingent consideration payable is classified as Level 3 because we use unobservable inputs to estimate fair value, including the probability of achieving certain earnings thresholds and appropriate discount rates. Changes in fair value of contingent consideration are recorded through operating expenses. Note Payable The fair value of our note payable is based on borrowing rates currently available to a market participant for loans with similar terms or maturity. The carrying amount of our note payable approximates fair value because the base interest rate charged varies with market conditions and the credit spread is commensurate with current market spreads for issuers of similar risk. The fair value of the note payable is classified as a Level 2 liability in the fair value hierarchy.