BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
Dec. 31, 2017
Accounting Policies [Abstract]
BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Recently Adopted Accounting Pronouncements In March 2016, the FASB issued ASU 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting." The amendments in this update changed how companies account for certain aspects of share-based payments to employees. We adopted the various amendments in ASU 2016-09 in our consolidated financial statements effective January 1, 2017 with no material effect at the date of adoption. On a prospective basis, as required, we recognize the income tax effects of the excess benefits or deduction deficiencies of share-based awards in the statement of income when the awards vest or are settled. Previously, these amounts were recorded as an adjustment to additional paid-in capital. In addition, these excess tax benefits or deduction deficiencies from share-based compensation plans, which were previously presented as a financing activity in our consolidated statement of cash flows, are now presented as an operating activity using a retrospective transition method for all periods presented. Finally, we elected to account for forfeitures of share-based awards with service conditions as they occur, which had no material effect on our consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments," which makes clarifications to how cash receipts and cash payments in certain transactions are presented and classified in the statement of cash flows. We adopted ASU 2016-15 on a retrospective basis effective January 1, 2017 with no effect on our consolidated statements of cash flows for any period presented. In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment." The ASU eliminates Step 2 from the goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities (including unrecognized assets and liabilities) following the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. Instead, under the amendments in this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. We adopted ASU 2017-04 on a prospective basis effective January 1, 2017 with no effect on our consolidated financial statements. Recently Issued Pronouncements Not Yet Adopted ASC 606 - New Revenue Accounting Standard In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)." The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP and permits the use of either the retrospective or modified retrospective transition method. The update requires significant additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments. ASU 2014-09, as amended by ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," is effective for years beginning after December 15, 2017, including interim periods, with early adoption permitted for years beginning after December 15, 2016. Since the issuance of ASU 2014-09, the FASB has issued additional interpretive guidance, including new accounting standards updates, that clarifies certain points of the standard and modifies certain requirements. We have performed a review of the requirements of the new revenue standard and have monitored the activity of the FASB and the transition resource group as it relates to specific interpretive guidance. We established a cross-functional implementation team to assess the effects of the new revenue standard in a multi-phase approach. In the first phase, we analyzed customer contracts for our most significant contract categories, applied the five-step model of the new standard to each contract category and compared the results to our current accounting practices. In the second phase, we quantified the potential effects, assessed additional contract categories and principal agent considerations, revised accounting policies and considered the effects on related disclosures and/or internal control over financial reporting. The third phase, which will complete our adoption and implementation of the new revenue standard, includes activities such as implementing parallel accounting and reporting for areas affected by the new standard, quantifying the cumulative-effect adjustment (including tax effects), evaluating and testing modified and newly implemented internal controls and revising financial statement disclosures. The new standard will change the amount and timing of revenue and expenses to be recognized under certain of our arrangement types. In addition, it could increase the administrative burden on our operations to properly account for customer contracts and provide the more expansive required disclosures. More judgment and estimates will be required when applying the requirements of the new standard than are required under existing GAAP, such as identifying performance obligations in contracts, estimating the amount of variable consideration to include in transaction price, allocating transaction price to each separate performance obligation and estimating expected periods of benefit for certain costs. We expect the timing of revenue to be recognized under ASU 2014-09 for our most significant contract category, core payment services, will be similar to the timing of revenue recognized under our current accounting practices. However, under the new standard, we will reflect revenue net of certain fees that we pay to third parties, including payment network fees, that we currently recognize as a component of operating expense under existing standards. This change in presentation will have no effect on the reported amount of operating income. We will also capitalize additional costs to obtain contracts with customers, as well as certain implementation and set-up costs, and, in some cases, may be required to amortize these costs and costs that we currently capitalize (such as capitalized customer acquisition costs) over a longer period. Finally, the new standard requires additional disclosures regarding our revenues and related capitalized contract costs. We plan to adopt ASU 2014-09, as well as other clarifications and technical guidance issued by the FASB related to this new revenue standard, effective as of January 1, 2018 applying the modified retrospective transition method, which will result in an adjustment to equity for the cumulative-effect of applying the standard to active customer contracts for which certain performance obligations were not completed at the date of initial application. Under this transition method, we would not recast the prior financial statements presented, therefore the new standard requires us to provide additional disclosures of the amount by which each financial statement line item is affected in the current reporting period during 2018, as compared to the guidance that was in effect before the change, and an explanation of the reasons for significant changes, if any. Our preliminary estimate is that we will record a net increase to retained earnings of approximately $50 million as of January 1, 2018, primarily due to the requirement to utilize longer amortization periods for signing bonuses and other sales commissions that are capitalized in connection with obtaining customer contracts. Previously, we amortized these capitalized costs over the term of the related contract. Under ASU 2014-09, we now expect to amortize these capitalized costs over the expected period of benefit, which is generally longer. The expected increase in retained earnings also reflects the capitalization of sales commissions and certain implementation and setup costs for new customers that were not previously capitalized. The expected adjustment to retained earnings is net of the estimated effect of income taxes related to the adjustments described above. ASC 842 - New Lease Accounting Standard In February 2016, the FASB issued ASU 2016-02, "Leases." The amendments in this update require lessees to recognize, on the balance sheet, assets and liabilities for the rights and obligations created by leases. In addition, several new disclosures will be required. In September 2017, the FASB issued ASU 2017-13, "Revenue Recognition" (Topic 605), "Revenue from Contracts with Customers" (Topic 606), "Leases" (Topic 840) and "Leases" (Topic 842), which provides additional implementation guidance on the previously issued ASU 2016-02. Although early adoption is permitted, we expect to adopt ASU 2016-02 when it becomes effective for us on January 1, 2019. As written, the standard would require a modified retrospective transition under which lessees must recognize and measure leases at the beginning of the earliest period presented. The FASB is currently considering an option to allow these entities to choose that transition method or to recognize the effects of applying the new standard as a cumulative-effect adjustment to retained earnings as of the adoption date, which would not require a recast of comparative periods. We have not completed our evaluation of the effect of ASU 2016-02 or ASU 2017-13 on our consolidated financial statements; however, we expect to recognize right of use assets and liabilities for our operating leases in the balance sheet upon adoption. To evaluate the potential effects of this new accounting standard on our consolidated financial statements, we are currently gathering information about our existing leases, which primarily include real estate leases for office space throughout the various global markets in which we conduct business. We expect that we will have to implement new accounting processes and internal controls to meet the requirements for financial reporting and disclosures of our leases and are coordinating with various internal stakeholders to evaluate, design and implement these new processes and controls. We are also evaluating the process by which we will maintain the necessary information about our leases and make the required calculations to support the requirements of the new accounting standard. We further expect these evaluation and implementation activities will continue throughout most of 2018 prior to the effective date of adoption on January 1, 2019. Other Accounting Standards Updates In August 2017, the FASB issued ASU 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities." The ASU expands and refines hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. In addition, the amendments in this update modify disclosure requirements for presentation of hedging activities. Those modifications include a tabular disclosure related to the effect on the income statement of fair value and cash flow hedges and eliminate the requirement to disclose the ineffective portion of the change in fair value of hedging instruments, if any. We will adopt ASU 2017-12 effective January 1, 2018 with no expected effect on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business." The ASU clarifies the definition of a business, which affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The new standard is intended to help companies and other organizations evaluate whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses, with the expectation that fewer will qualify as acquisitions (or disposals) of businesses. The ASU became effective for us on January 1, 2018. These amendments will be applied prospectively from the date of adoption. The effect of ASU 2017-01 will be dependent upon the nature of future acquisitions or dispositions that we make, if any. In October 2016, the FASB issued ASU 2016-16, "Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory." The amendments in this update state that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory, such as intellectual property and property and equipment, when the transfer occurs. We will adopt ASU 2016-16 effective January 1, 2018 with no expected effect on our consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." The amendments in this update change how companies measure and recognize credit impairment for many financial assets. The new expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets (including trade receivables) that are in the scope of the update. The update also made amendments to the current impairment model for held-to-maturity and available-for-sale debt securities and certain guarantees. The guidance will become effective for us on January 1, 2020. Early adoption is permitted for periods beginning on or after January 1, 2019. We are evaluating the effect of ASU 2016-13 on our consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities." The amendments in this update address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. The amendments in this update supersede the guidance to classify equity securities with readily determinable fair values into different categories (that is, trading or available-for-sale) and require equity securities (including other ownership interests, such as partnerships, unincorporated joint ventures and limited liability companies) to be measured at fair value with changes in the fair value recognized through earnings. Equity investments that are accounted for under the equity method of accounting or result in consolidation of an investee are not included within the scope of this update. The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value either upon the occurrence of an observable price change or upon identification of an impairment. The amendments also require enhanced disclosures about those investments. We will adopt ASU 2016-01 effective January 1, 2018 with no expected effect on our consolidated financial statements.

Recently Adopted Accounting Pronouncements

In March 2016, the FASB issued ASU 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting." The amendments in this update changed how companies account for certain aspects of share-based payments to employees. We adopted the various amendments in ASU 2016-09 in our consolidated financial statements effective January 1, 2017 with no material effect at the date of adoption. On a prospective basis, as required, we recognize the income tax effects of the excess benefits or deduction deficiencies of share-based awards in the statement of income when the awards vest or are settled. Previously, these amounts were recorded as an adjustment to additional paid-in capital. In addition, these excess tax benefits or deduction deficiencies from share-based compensation plans, which were previously presented as a financing activity in our consolidated statement of cash flows, are now presented as an operating activity using a retrospective transition method for all periods presented. Finally, we elected to account for forfeitures of share-based awards with service conditions as they occur, which had no material effect on our consolidated financial statements.

In August 2016, the FASB issued ASU 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments," which makes clarifications to how cash receipts and cash payments in certain transactions are presented and classified in the statement of cash flows. We adopted ASU 2016-15 on a retrospective basis effective January 1, 2017 with no effect on our consolidated statements of cash flows for any period presented.

In January 2017, the FASB issued ASU 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment." The ASU eliminates Step 2 from the goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities (including unrecognized assets and liabilities) following the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. Instead, under the amendments in this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. We adopted ASU 2017-04 on a prospective basis effective January 1, 2017 with no effect on our consolidated financial statements.

Recently Issued Pronouncements Not Yet Adopted

ASC 606 - New Revenue Accounting Standard

In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)." The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP and permits the use of either the retrospective or modified retrospective transition method. The update requires significant additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments. ASU 2014-09, as amended by ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," is effective for years beginning after December 15, 2017, including interim periods, with early adoption permitted for years beginning after December 15, 2016. Since the issuance of ASU 2014-09, the FASB has issued additional interpretive guidance, including new accounting standards updates, that clarifies certain points of the standard and modifies certain requirements.

We have performed a review of the requirements of the new revenue standard and have monitored the activity of the FASB and the transition resource group as it relates to specific interpretive guidance. We established a cross-functional implementation team to assess the effects of the new revenue standard in a multi-phase approach. In the first phase, we analyzed customer contracts for our most significant contract categories, applied the five-step model of the new standard to each contract category and compared the results to our current accounting practices. In the second phase, we quantified the potential effects, assessed additional contract categories and principal agent considerations, revised accounting policies and considered the effects on related disclosures and/or internal control over financial reporting. The third phase, which will complete our adoption and implementation of the new revenue standard, includes activities such as implementing parallel accounting and reporting for areas affected by the new standard, quantifying the cumulative-effect adjustment (including tax effects), evaluating and testing modified and newly implemented internal controls and revising financial statement disclosures.

The new standard will change the amount and timing of revenue and expenses to be recognized under certain of our arrangement types. In addition, it could increase the administrative burden on our operations to properly account for customer contracts and provide the more expansive required disclosures. More judgment and estimates will be required when applying the requirements of the new standard than are required under existing GAAP, such as identifying performance obligations in contracts, estimating the amount of variable consideration to include in transaction price, allocating transaction price to each separate performance obligation and estimating expected periods of benefit for certain costs. We expect the timing of revenue to be recognized under ASU 2014-09 for our most significant contract category, core payment services, will be similar to the timing of revenue recognized under our current accounting practices. However, under the new standard, we will reflect revenue net of certain fees that we pay to third parties, including payment network fees, that we currently recognize as a component of operating expense under existing standards. This change in presentation will have no effect on the reported amount of operating income. We will also capitalize additional costs to obtain contracts with customers, as well as certain implementation and set-up costs, and, in some cases, may be required to amortize these costs and costs that we currently capitalize (such as capitalized customer acquisition costs) over a longer period. Finally, the new standard requires additional disclosures regarding our revenues and related capitalized contract costs.

We plan to adopt ASU 2014-09, as well as other clarifications and technical guidance issued by the FASB related to this new revenue standard, effective as of January 1, 2018 applying the modified retrospective transition method, which will result in an adjustment to equity for the cumulative-effect of applying the standard to active customer contracts for which certain performance obligations were not completed at the date of initial application. Under this transition method, we would not recast the prior financial statements presented, therefore the new standard requires us to provide additional disclosures of the amount by which each financial statement line item is affected in the current reporting period during 2018, as compared to the guidance that was in effect before the change, and an explanation of the reasons for significant changes, if any.

Our preliminary estimate is that we will record a net increase to retained earnings of approximately $50 million as of January 1, 2018, primarily due to the requirement to utilize longer amortization periods for signing bonuses and other sales commissions that are capitalized in connection with obtaining customer contracts. Previously, we amortized these capitalized costs over the term of the related contract. Under ASU 2014-09, we now expect to amortize these capitalized costs over the expected period of benefit, which is generally longer. The expected increase in retained earnings also reflects the capitalization of sales commissions and certain implementation and setup costs for new customers that were not previously capitalized. The expected adjustment to retained earnings is net of the estimated effect of income taxes related to the adjustments described above.

ASC 842 - New Lease Accounting Standard

In February 2016, the FASB issued ASU 2016-02, "Leases." The amendments in this update require lessees to recognize, on the balance sheet, assets and liabilities for the rights and obligations created by leases. In addition, several new disclosures will be required. In September 2017, the FASB issued ASU 2017-13, "Revenue Recognition" (Topic 605), "Revenue from Contracts with Customers" (Topic 606), "Leases" (Topic 840) and "Leases" (Topic 842), which provides additional implementation guidance on the previously issued ASU 2016-02.

Although early adoption is permitted, we expect to adopt ASU 2016-02 when it becomes effective for us on January 1, 2019. As written, the standard would require a modified retrospective transition under which lessees must recognize and measure leases at the beginning of the earliest period presented. The FASB is currently considering an option to allow these entities to choose that transition method or to recognize the effects of applying the new standard as a cumulative-effect adjustment to retained earnings as of the adoption date, which would not require a recast of comparative periods. We have not completed our evaluation of the effect of ASU 2016-02 or ASU 2017-13 on our consolidated financial statements; however, we expect to recognize right of use assets and liabilities for our operating leases in the balance sheet upon adoption.

To evaluate the potential effects of this new accounting standard on our consolidated financial statements, we are currently gathering information about our existing leases, which primarily include real estate leases for office space throughout the various global markets in which we conduct business. We expect that we will have to implement new accounting processes and internal controls to meet the requirements for financial reporting and disclosures of our leases and are coordinating with various internal stakeholders to evaluate, design and implement these new processes and controls. We are also evaluating the process by which we will maintain the necessary information about our leases and make the required calculations to support the requirements of the new accounting standard. We further expect these evaluation and implementation activities will continue throughout most of 2018 prior to the effective date of adoption on January 1, 2019.

Other Accounting Standards Updates

In August 2017, the FASB issued ASU 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities." The ASU expands and refines hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. In addition, the amendments in this update modify disclosure requirements for presentation of hedging activities. Those modifications include a tabular disclosure related to the effect on the income statement of fair value and cash flow hedges and eliminate the requirement to disclose the ineffective portion of the change in fair value of hedging instruments, if any. We will adopt ASU 2017-12 effective January 1, 2018 with no expected effect on our consolidated financial statements.

In January 2017, the FASB issued ASU 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business." The ASU clarifies the definition of a business, which affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The new standard is intended to help companies and other organizations evaluate whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses, with the expectation that fewer will qualify as acquisitions (or disposals) of businesses. The ASU became effective for us on January 1, 2018. These amendments will be applied prospectively from the date of adoption. The effect of ASU 2017-01 will be dependent upon the nature of future acquisitions or dispositions that we make, if any.

In October 2016, the FASB issued ASU 2016-16, "Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory." The amendments in this update state that an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory, such as intellectual property and property and equipment, when the transfer occurs. We will adopt ASU 2016-16 effective January 1, 2018 with no expected effect on our consolidated financial statements.

In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." The amendments in this update change how companies measure and recognize credit impairment for many financial assets. The new expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets (including trade receivables) that are in the scope of the update. The update also made amendments to the current impairment model for held-to-maturity and available-for-sale debt securities and certain guarantees. The guidance will become effective for us on January 1, 2020. Early adoption is permitted for periods beginning on or after January 1, 2019. We are evaluating the effect of ASU 2016-13 on our consolidated financial statements.

In January 2016, the FASB issued ASU 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities." The amendments in this update address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. The amendments in this update supersede the guidance to classify equity securities with readily determinable fair values into different categories (that is, trading or available-for-sale) and require equity securities (including other ownership interests, such as partnerships, unincorporated joint ventures and limited liability companies) to be measured at fair value with changes in the fair value recognized through earnings. Equity investments that are accounted for under the equity method of accounting or result in consolidation of an investee are not included within the scope of this update. The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value either upon the occurrence of an observable price change or upon identification of an impairment. The amendments also require enhanced disclosures about those investments. We will adopt ASU 2016-01 effective January 1, 2018 with no expected effect on our consolidated financial statements.