Equity [Abstract] Changes in accumulated other comprehensive loss by component, net of income taxes Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Payables and Accruals [Abstract] Trade accounts payable Accounts Payable, Current Client deposits Contract With Customer, Liability, Customer Deposits, Current Contract With Customer, Liability, Customer Deposits, Current Accrued compensation and benefits Accrued Employee Benefits, Current Other accrued expenses Other Accrued Liabilities, Current Total Accounts Payable and Accrued Liabilities, Current Noncontrolling Interest [Abstract] Schedule of Redeemable Noncontrolling Interest Activity Redeemable Noncontrolling Interest [Table Text Block] Fair Value Disclosures [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Recurring Fair Value, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Cash flow hedges Cash Flow Hedge Derivative Instrument Assets at Fair Value Contingent consideration Business Combination, Contingent Consideration, Liability Redeemable Noncontrolling Interest Noncontrolling Interest Disclosure [Text Block] Revenue from Contract with Customer [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Processing and services Processing And Services [Member] Processing And Services [Member] Product Product [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Performance obligations expected to be satisfied Revenue, Remaining Performance Obligation, Amount Performance obligations expected to be satisfied, expected timing Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Earnings Per Share [Abstract] Weighted-average common shares outstanding used for the calculation of net income attributable to Fiserv, Inc. per share – basic (in shares) Weighted Average Number of Shares Outstanding, Basic Common stock equivalents (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Weighted-average common shares outstanding used for the calculation of net income attributable to Fiserv, Inc. per share – diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Line of Credit Line of Credit [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Notes Senior Notes [Member] Receivable securitized loan Secured Debt [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Term loan facility Term Loan Facility [Member] Term Loan Facility [Member] Revolving credit facility Revolving Credit Facility [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2.7% senior notes due 2020 2.7% Senior Notes Due 2020 [Member] 2.7% Senior Notes Due 2020 [Member] 4.75% senior notes due 2021 4.75% Senior Notes Due 2021 [Member] 4.75% Senior Notes Due 2021 [Member] 3.5% senior notes due 2022 3.5% Senior Notes Due 2022 [Member] 3.5% Senior Notes Due 2022 [Member] 3.8% senior notes due 2023 3.8% Senior Notes Due 2023 [Member] 3.8% Senior Notes Due 2023 [Member] 0.375% senior notes due 2023 0.375% Senior Notes Due July 2023 [Member] 0.375% Senior Notes Due July 2023 [Member] 2.75% senior notes due 2024 2.75% Senior Notes Due July 2024 [Member] 2.75% Senior Notes Due July 2024 [Member] 3.85% senior notes due 2025 3.85% Senior Notes Due 2025 [Member] 3.85% Senior Notes Due 2025 [Member] 2.25% senior notes due 2025 2.25% Senior Notes Due July 2025 [Member] 2.25% Senior Notes Due July 2025 [Member] 3.2% senior notes due 2026 3.2% Senior Notes Due July 2026 [Member] 3.2% Senior Notes Due July 2026 [Member] 1.125% senior notes due 2027 1.125% Senior Notes Due July 2027 [Member] 1.125% Senior Notes Due July 2027 [Member] 4.2% senior notes due 2028 4.2% Senior Notes Due 2028 [Member] 4.2% Senior Notes Due 2028 [Member] 3.5% senior notes due 2029 3.5% Senior Notes Due July 2029 [Member] 3.5% Senior Notes Due July 2029 [Member] 1.625% senior notes due 2030 1.625% Senior Notes Due July 2030 [Member] 1.625% Senior Notes Due July 2030 [Member] 3.0% senior notes due 2031 3.0% Senior Notes Due July 2031 [Member] 3.0% Senior Notes Due July 2031 [Member] 4.4% senior notes due 2049 4.4% Senior Notes Due July 2049 [Member] 4.4% Senior Notes Due July 2049 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Short-term debt and current maturities of long-term debt: Debt, Current [Abstract] Short-term debt and current maturities of long-term debt Debt, Current Finance lease and other financing obligations Finance Lease, Liability And Other, Current Finance Lease, Liability And Other, Current Long-term debt: Long-term Debt, Other Disclosures [Abstract] Long-term debt Long-term Debt, Gross Unamortized discount and unamortized deferred financing costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Finance lease and other financing obligations Finance Lease, Liability And Other, Noncurrent Finance Lease, Liability And Other, Noncurrent Total long-term debt Long-term Debt and Lease Obligation Revenue Recognition Revenue from Contract with Customer [Text Block] Share-based Payment Arrangement [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Equity Interest Type [Axis] Equity Interest Type [Axis] Equity Interest Issued or Issuable, Type [Domain] Equity Interest Issued or Issuable, Type [Domain] Equity Awards Equity Awards [Member] Equity Awards [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] First Data First Data [Member] First Data [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Stock options Share-based Payment Arrangement, Option [Member] Employee stock purchase plan Employee Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Period that awards will expire (in years) Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Employee purchase percentage of the closing price of common stock Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent Compensation expense recognized related to discount on purchase date (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date Share-based compensation expense Share-based Payment Arrangement, Expense Unrecognized compensation cost Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Weighted-average period unrecognized compensation cost will be recognized Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Share-based awards, stock options, exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Entity shares issued per acquiree share (in shares) Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Entity Shares Issued Per Acquiree Share Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Entity Shares Issued Per Acquiree Share Stock price achievement of common stock (in dollars per share) Business Combination, Equity Awards Granted At Initial Public Offering Subject To Vesting Upon Stock Price Achievement, Share Price Business Combination, Equity Awards Granted At Initial Public Offering Subject To Vesting Upon Stock Price Achievement, Share Price Fair value of stock exchanged for Fiserv, Inc. shares Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Weighted-average estimated fair value per share of stock options granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Share-based awards available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Shares issued under equity plan (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Schedule of Stockholders Equity Schedule of Stockholders Equity [Table Text Block] Supplemental Cash Flow Elements [Abstract] Schedule of supplemental cash flow information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Retirement Benefits [Abstract] Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Operating lease, liability Operating Lease, Liability Operating lease, right-of-use asset Operating Lease, Right-of-Use Asset Segment Reporting [Abstract] Schedule of segment reporting information Schedule of Segment Reporting Information, by Segment [Table Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Leases [Abstract] Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Lessee lease term Lessee, Lease, Term Of Contract Lessee, Lease, Term Of Contract Operating leases, rent expense Operating Leases, Rent Expense Lessor lease term Lessor, Operating And Sales-Type Lease, Term of Contract Lessor, Operating And Sales-Type Lease, Term of Contract Income Tax Disclosure [Abstract] Schedule of Income Tax Provision and Effective Income Tax Rate Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Balance Sheet Classification of Lease Assets and Liabilities Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Schedule of Cost, Supplemental Cash Flow and Other Information Related to Leases Lease, Cost [Table Text Block] Operating Lease Maturity under ASC 842 Lessee, Operating Lease, Liability, Maturity [Table Text Block] Finance Lease Maturity under ASC 842 Finance Lease, Liability, Maturity [Table Text Block] Operating Lease Maturity under ASC 840 Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Components of Lease Income Operating Lease, Lease Income [Table Text Block] Schedule of Components of Lease Income Direct Financing Lease, Lease Income [Table Text Block] Schedule of Components of Lease Income Sales-type Lease, Lease Income [Table Text Block] Schedule of Components of Net Investment in Sales-Type and Direct Financing Leases Net Investment In Lease [Table Text Block] Net Investment In Lease [Table Text Block] Schedule of Maturities of Future Minimum Lease Payments Sales-type and Direct Financing Leases, Lease Receivable, Maturity [Table Text Block] Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Expected life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Average risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected volatility (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate Expected dividend yield (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Operating lease assets Finance lease assets Finance Lease, Right-of-Use Asset Total lease assets Lease, Right-Of-Use Asset Lease, Right-Of-Use Asset Current operating lease liabilities Operating Lease, Liability, Current Finance lease obligations Finance Lease, Liability, Current Noncurrent operating lease liabilities Operating Lease, Liability, Noncurrent Finance lease and other financing obligations Finance Lease, Liability, Noncurrent Total lease liabilities Lease, Liability Lease, Liability Statement of Comprehensive Income [Abstract] Statement [Table] Statement [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Cost of Services Cost Of Services [Member] Cost Of Services [Member] Interest Expense Interest Expense [Member] Statement [Line Items] Statement [Line Items] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other comprehensive (loss) income: Other Comprehensive Income (Loss), Net of Tax [Abstract] Fair market value adjustment on cash flow hedges, net of income tax benefit of $1 million, $2 million, $46 million and $4 million Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Reclassification adjustment for net realized (gains) losses on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Total other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to Fiserv, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Leases Lessee, Operating Leases [Text Block] Leases Lessee, Finance Leases [Text Block] Leases Lessor, Operating Leases [Text Block] Leases Lessor, Sales-type Leases [Text Block] Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Equity Method Investments and Joint Ventures [Abstract] Total current assets Equity Method Investment, Summarized Financial Information, Current Assets Total long-term assets Equity Method Investment, Summarized Financial Information, Noncurrent Assets Total assets Equity Method Investment, Summarized Financial Information, Assets Total current liabilities Equity Method Investment, Summarized Financial Information, Current Liabilities Total long-term liabilities Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities Total liabilities Equity Method Investment, Summarized Financial Information, Liabilities Total revenues Equity Method Investment, Summarized Financial Information, Revenue Total expenses Equity Method Investment, Summarized Financial Information, Operating Expenses Equity Method Investment, Summarized Financial Information, Operating Expenses Operating income Equity Method Investment, Summarized Financial Information, Operating Income (Loss) Equity Method Investment, Summarized Financial Information, Operating Income (Loss) Net income Equity Method Investment, Summarized Financial Information, Net Income (Loss) Income from investments in unconsolidated affiliates Equity Method Investment, Summarized Financial Information, Net Income (Loss) From Investments In Unconsolidated Affiliates Equity Method Investment, Summarized Financial Information, Net Income (Loss) From Investments In Unconsolidated Affiliates Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Contract assets Contract with Customer, Asset, after Allowance for Credit Loss Contract liabilities Contract with Customer, Liability Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities from continuing operations: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and other amortization Other Depreciation and Amortization Amortization of acquisition-related intangible assets Amortization of Acquisition-Related Intangible Assets The aggregate expense charged against earnings to allocate the cost of acquired intangible assets. As a noncash expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method. Amortization of financing costs, debt discounts and other Amortization Of Debt Issuance Costs, Discounts And Other Amortization Of Debt Issuance Costs, Discounts And Other Net foreign currency gain on financing activities Foreign Currency Transaction Gain (Loss), before Tax Share-based compensation Share-based Payment Arrangement, Noncash Expense Deferred income taxes Deferred Income Tax Expense (Benefit) Gain on sale of business Gain (Loss) on Disposition of Business Income from investments in unconsolidated affiliates Income (Loss) from Equity Method Investments Distributions from unconsolidated affiliates Proceeds from Equity Method Investment, Distribution Settlement of interest rate hedge contracts Unrealized Gain (Loss) on Derivatives Other operating activities Other Operating Activities, Cash Flow Statement Changes in assets and liabilities, net of effects from acquisitions and dispositions: Increase (Decrease) in Operating Capital [Abstract] Trade accounts receivable Increase (Decrease) in Accounts Receivable Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Contract costs Increase (Decrease) in Contract with Customer, Asset Accounts payable and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Contract liabilities Increase (Decrease) in Contract with Customer, Liability Net cash provided by operating activities from continuing operations Net Cash Provided by (Used in) Operating Activities, Continuing Operations Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures, including capitalization of software costs Payments to Acquire Property, Plant, and Equipment Proceeds from sale of businesses Proceeds from Divestiture of Businesses Payments for acquisition of business, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Distributions from unconsolidated affiliates Proceeds from Equity Method Investment, Distribution, Return of Capital Purchases of investments Payments to Acquire Investments Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash (used in) provided by investing activities from continuing operations Net Cash Provided by (Used in) Investing Activities, Continuing Operations Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Debt proceeds Proceeds from Issuance of Long-term Debt Debt repayments Repayment of Long-term Debt, Long-term Lease Obligation, and Capital Security Payments of debt financing, redemption and other costs Payments of Financing Costs Proceeds from issuance of treasury stock Proceeds from Issuance or Sale of Equity Purchases of treasury stock, including employee shares withheld for tax obligations Payments For Repurchase Of Common Stock And Payments Related To Tax Withholding For Share Based Compensation The cash outflow to reacquire common stock during the period and to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award. Distributions paid to noncontrolling interest and redeemable noncontrolling interest Payments of Ordinary Dividends, Noncontrolling Interest Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash provided by (used in) financing activities from continuing operations Net Cash Provided by (Used in) Financing Activities, Continuing Operations Effect of exchange rate changes on cash, cash equivalents, and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Net change in cash, cash equivalents, and restricted cash from continuing operations Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Continuing Operations Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Continuing Operations Net cash flows from discontinued operations Net Cash Provided by (Used in) Discontinued Operations Cash, cash equivalents, and restricted cash beginning balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Cash, cash equivalents, and restricted cash ending balance Discontinued operations cash flow information: Net Cash Provided by (Used in) Discontinued Operations [Abstract] Net cash used in operating activities Cash Provided by (Used in) Operating Activities, Discontinued Operations Net cash provided by investing activities Cash Provided by (Used in) Investing Activities, Discontinued Operations Net change in cash and cash equivalents from discontinued operations Disaggregation of revenue Disaggregation of Revenue [Table Text Block] Contract with customer, asset and liabilities Contract with Customer, Asset and Liability [Table Text Block] Schedule of remaining performance obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Statement of Financial Position [Abstract] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships Customer-Related Intangible Assets [Member] Other intangible assets, net Other Intangible Assets [Member] Assets Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations Trade accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Settlement assets Settlement Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Intangible assets, net Finite-Lived Intangible Assets, Net Goodwill Goodwill Contract costs, net Capitalized Contract Cost, Net Investments in unconsolidated affiliates Equity Method Investments Other long-term assets Other Assets, Noncurrent Total assets Assets Liabilities and Shareholders’ Equity Liabilities and Equity [Abstract] Accounts payable and accrued expenses Short-term and current maturities of long-term debt Long-term Debt and Lease Obligation, Current Contract liabilities Contract with Customer, Liability, Current Settlement obligations Settlement Liabilities, Current Total current liabilities Liabilities, Current Long-term debt Deferred income taxes Deferred Income Tax Liabilities, Net Long-term contract liabilities Contract with Customer, Liability, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (see Note 23) Commitments and Contingencies Redeemable noncontrolling interest Redeemable Noncontrolling Interest, Equity, Carrying Amount Fiserv, Inc. shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, no par value: 25.0 million shares authorized; none issued Preferred Stock, Value, Issued Common stock, $0.01 par value: 1,800.0 million shares authorized; 791.4 million shares issued Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Treasury stock, at cost, 110.6 million and 398.9 million shares Treasury Stock, Value Total Fiserv, Inc. shareholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Sales-Type Leases Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract] 2019 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Next Twelve Months 2020 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years 2021 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years 2022 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years 2023 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years Thereafter Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter Total minimum lease payments Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received Long-term Debt Long-term Debt [Text Block] Minimum lease payments Residual values Sales-Type And Direct Financing Leases, Unguaranteed Residual Asset Sales-Type And Direct Financing Leases, Unguaranteed Residual Asset Less: Unearned interest income Sales-Type And Direct Financing Leases, Unearned Interest Income Sales-Type And Direct Financing Leases, Unearned Interest Income Net investment in leases Net Investment in Lease Defined Benefit Plan, Expected Future Benefit Payment [Abstract] Defined Benefit Plan, Expected Future Benefit Payment [Abstract] 2019 Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year 2020 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Thereafter Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Total Defined Benefit Plan, Expected Future Benefit Payment, Total Defined Benefit Plan, Expected Future Benefit Payment, Total Recent Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Intangible Assets Intangible Assets Disclosure [Text Block] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Foreign currency forward exchange contracts Foreign Exchange Contract [Member] Foreign currency forward exchange contracts - Euro and British pound denominated senior notes Foreign Exchange Contract - Euro And British Pound Denominated Senior Notes [Member] Foreign Exchange Contract - Euro And British Pound Denominated Senior Notes [Member] Foreign currency forward exchange contracts - Euro and British pound denominated cash Foreign Exchange Contract - Euro And British Pound Denominated Cash [Member] Foreign Exchange Contract - Euro And British Pound Denominated Cash [Member] Debt Instrument, Amortization, Period [Axis] Debt Instrument, Amortization, Period [Axis] Debt Instrument, Amortization, Period [Axis] Debt Instrument, Amortization, Period [Domain] Debt Instrument, Amortization, Period [Domain] [Domain] for Debt Instrument, Amortization, Period [Axis] Debt Instrument, Amortization, Period One Debt Instrument, Amortization, Period One [Member] Debt Instrument, Amortization, Period One [Member] Debt Instrument, Amortization, Period Two Debt Instrument, Amortization, Period Two [Member] Debt Instrument, Amortization, Period Two [Member] Debt Instrument, Amortization, Period Three Debt Instrument, Amortization, Period Three [Member] Debt Instrument, Amortization, Period Three [Member] Debt Instrument, Option [Axis] Debt Instrument, Option [Axis] Debt Instrument, Option [Axis] Debt Instrument, Option [Domain] Debt Instrument, Option [Domain] [Domain] for Debt Instrument, Option [Axis] Debt Instrument, Option, One Debt Instrument, Option, One [Member] Debt Instrument, Option, One [Member] Debt Instrument, Option, Two Debt Instrument, Option, Two [Member] Debt Instrument, Option, Two [Member] Foreign Line of Credit Foreign Line of Credit [Member] Bridge Loan Bridge Loan [Member] Revolving Credit Facility Senior Unsecured Bridge Term Loan Facility Senior Unsecured Bridge Term Loan Facility [Member] Senior Unsecured Bridge Term Loan Facility [Member] Senior Unsecured Term Loan Facility Senior Unsecured Term Loan Facility [Member] Senior Unsecured Term Loan Facility [Member] Senior Unsecured Term Loan Facility, Loans With Three Year Maturity Senior Unsecured Term Loan Facility, Loans With Three Year Maturity [Member] Senior Unsecured Term Loan Facility, Loans With Three Year Maturity [Member] Senior Unsecured Term Loan Facility, Loans With Five Year Maturity Senior Unsecured Term Loan Facility, Loans With Five Year Maturity [Member] Senior Unsecured Term Loan Facility, Loans With Five Year Maturity [Member] Debt term Debt Instrument, Term Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Debt costs Debt Related Commitment Fees and Debt Issuance Costs Debt instrument terms for line of credit, debt to income ratio Debt Instrument Terms For Line Of Credit, Debt To Income Ratio Debt Instrument Terms For Line Of Credit, Debt To Income Ratio Revolving credit, increase limit Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit Variable interest rate (as a percent) Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate Amortization rate Line Of Credit Facility, Amortization Rate Line Of Credit Facility, Amortization Rate Debt instrument, face amount Debt Instrument, Face Amount Carrying value of debt Long-term Debt Debt instrument, interest rate Realized foreign currency transaction gains (losses) Foreign Currency Transaction Gain (Loss), Realized Extinguishment of debt Extinguishment of Debt, Amount Repayment of First Data debt Business Combination, Consideration Transferred, Liabilities Incurred Amounts outstanding on lines of credit Line of Credit, Current Weighted average interest rate percentage Line of Credit Facility, Interest Rate at Period End Average interest rate Debt, Weighted Average Interest Rate Accounts receivable from securitization Accounts Receivable from Securitization Borrowings with receivables used as collateral Projected benefit obligation, discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Net periodic benefit expense, discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Net periodic benefit expense, expected long-term return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Preferred stock, par value (in dollars per share) Preferred Stock, No Par Value Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Treasury stock (in shares) Treasury Stock, Shares Service costs Defined Benefit Plan, Service Cost Interest costs Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Net periodic benefit expense Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Accounting Policies [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Merchant credit losses Merchant Credit Losses [Member] Merchant Credit Losses [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Percentage of business acquired Business Acquisition, Percentage of Voting Interests Acquired Restricted cash and cash equivalents Restricted Cash and Cash Equivalents, Noncurrent Aggregate merchant credit losses incurred Loss Contingency, Loss in Period Collateral held Loss Contingency, Collateral Held Loss Contingency, Collateral Held Loss contingency accrual Loss Contingency Accrual Interest expense Interest Expense Interest income Investment Income, Interest Business Combinations [Abstract] Acquisitions Business Combination Disclosure [Text Block] Income Taxes Income Tax Disclosure [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Acquired software and technology Acquired Software And Technology [Member] Purchased software applications and internally developed software for sale, licensing or long-term internal use acquired in a business combination. Trade names Trade Names [Member] Capitalized software development costs Capitalized Software Development Costs [Member] Internally developed software for sale, licensing or long-term internal use (classified as intangible assets). Purchased software Computer Software, Intangible Asset [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Book Value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Share-Based Compensation Share-based Payment Arrangement [Text Block] Investment [Table] Investment [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Fair value Estimate of Fair Value Measurement [Member] Carrying value Reported Value Measurement [Member] Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Investment [Line Items] Investment [Line Items] Total debt Debt Instrument, Fair Value Disclosure Fair value of line of credit Lines of Credit, Fair Value Disclosure Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Sagent Auto, LLC Sagent Auto, LLC [Member] Sagent Auto, LLC [Member] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Financial Guarantee Financial Guarantee [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity Affiliated Entity [Member] Variable-Rate Term Loan Facilities Due March 2023 Variable-Rate Term Loan Facilities Due March 2023 [Member] Variable-Rate Term Loan Facilities Due March 2023 [Member] Variable-Rate Revolving Credit Facilities Due March 2023 Variable-Rate Revolving Credit Facilities Due March 2023 [Member] Variable-Rate Revolving Credit Facilities Due March 2023 [Member] Term Loan Facilities Term Loan Facilities [Member] Term Loan Facility [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Financial Financial Institution Services Segment [Member] Financial Institution Services Segment Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Fiserv Automotive Solutions, LLC Fiserv Automotive Solutions, LLC [Member] Fiserv Automotive Solutions, LLC [Member] Lending Solutions Business Lending Solutions Business [Member] Lending Solutions Business [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Controlling interest sold Sale of Business, Percentage of Ownership Sold In Transaction Sale of Business, Percentage of Ownership Sold In Transaction Pre-tax gain on sale Gain on sale of businesses, tax Gain (Loss) on Disposition of Business, Tax Gain (Loss) on Disposition of Business, Tax Remeasurement of retained interests Deconsolidation, Revaluation of Retained Investment, Gain (Loss), Amount Percentage of interest owned in affiliate Equity Method Investment, Ownership Percentage Amount outstanding Long-term Line of Credit Long-term liability Other (expense) income Nonoperating Income (Expense) Revenue Revenue from Contract with Customer, Excluding Assessed Tax Pre-tax gain related to merger Equity Method Investment, Realized Gain (Loss) on Disposal Gain related to merger, tax Equity Method Investment, Realized Gain (Loss) on Disposal, Tax Equity Method Investment, Realized Gain (Loss) on Disposal, Tax Increase in borrowing capacity Line of Credit Facility, Increase (Decrease), Net Guarantor obligations Guarantor Obligations, Current Carrying Value Number of affiliates accounted for as equity method investments Number Of Affiliates Accounted For As Equity Method Investments Number Of Affiliates Accounted For As Equity Method Investments Cash distributions from unconsolidated affiliate Proceeds from Equity Method Investment, Distribution, Operating and Investing Activities Proceeds from Equity Method Investment, Distribution, Operating and Investing Activities Equity securities without a readily determinable fair value Equity Securities without Readily Determinable Fair Value, Amount Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] Domestic Plan [Member] Domestic Plan [Member] U.K. plan UNITED KINGDOM U.S. and other plans United States And Other Foreign Pension Plans Defined Benefit [Member] United States And Other Foreign Pension Plans Defined Benefit [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Plan benefit obligations Defined Benefit Plan, Benefit Obligation Fair value of plan assets Defined Benefit Plan, Plan Assets, Amount Net pension assets (liabilities), Funded status of the plans Defined Benefit Plan, Funded (Unfunded) Status of Plan Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Operating Leases, under ASC 842 Lessee, Operating Lease, Liability, Payment, Due [Abstract] Remainder of 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less: Interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of lease liabilities Finance Leases, under ASC 842 Finance Lease, Liability, Payment, Due [Abstract] Remainder of 2019 Finance Lease, Liability, Payments, Remainder of Fiscal Year 2020 Finance Lease, Liability, Payments, Due Year Two 2021 Finance Lease, Liability, Payments, Due Year Three 2022 Finance Lease, Liability, Payments, Due Year Four 2023 Finance Lease, Liability, Payments, Due Year Five Thereafter Finance Lease, Liability, Payments, Due after Year Five Total lease payments Finance Lease, Liability, Payment, Due Less: Interest Finance Lease, Liability, Undiscounted Excess Amount Present value of lease liabilities Finance Lease, Liability Operating lease payments related to options to extend lease terms that are reasonably certain of being exercised Lessee, Operating Lease, Liability, Option To Extend Lessee, Operating Lease, Liability, Option To Extend Minimum operating lease payments for leases signed but not yet commenced Lessee, Operating Lease, Liability, Lease Not Yet Commenced Lessee, Operating Lease, Liability, Lease Not Yet Commenced Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Equipment Equipment [Member] Operating leases not yet commenced, term Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract Operating Leases, under ASC 840 Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Product First Data First Data Segment [Member] First Data Segment [Member] Payments Payments And Industry Products Segment [Member] Payments and Industry Products Segment Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating segments Operating Segments [Member] Corporate and Other Corporate Reconciling Items And Eliminations [Member] Corporate Reconciling Items And Eliminations [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Operating income Operating Income (Loss) Other intangible assets Elan Financial Services Elan Financial Services [Member] Elan Financial Services [Member] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Trade accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Settlement assets Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Settlement Assets Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Settlement Assets Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Finite-lived intangibles assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Investments in unconsolidated affiliates Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Equity Method Investments Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Equity Method Investments Other long-term assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Total assets acquired Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Assets Acquired Including Goodwill Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Assets Acquired Including Goodwill Accounts payable and accrued expenses Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Accounts Payable And Accrued Expenses Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Accounts Payable And Accrued Expenses Short-term and current maturities of long-term debt Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Debt, Current Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Debt, Current Contract liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Contract With Customer, Liability, Current Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Current Liabilities, Contract With Customer, Liability, Current Settlement obligations Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Settlement Liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Settlement Liabilities Deferred income taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Long-term contract liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Contract With Customer, Liability, NonCurrent Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Contract With Customer, Liability, NonCurrent Long-term debt and other long-term liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Accounts payable and other current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Net assets acquired Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Redeemable noncontrolling interest Business Combination, Acquisition Of Less Than 100 Percent, Redeemable Noncontrolling Interest, Fair Value Business Combination, Acquisition Of Less Than 100 Percent, Redeemable Noncontrolling Interest, Fair Value Noncontrolling interests Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value Total purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest Subscriber funds Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability Shares Used in Computing Net Income Per Share Attributable to Fiserv, Inc. Earnings Per Share [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill, beginning balance Acquisitions and valuation adjustments (see Note 4) Goodwill, Acquired During Period Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Goodwill, ending balance Operating lease cost Operating Lease, Cost Finance lease cost Finance Lease, Cost 1 [Abstract] Finance Lease, Cost 1 [Abstract] Amortization of right-of-use assets Finance Lease, Right-of-Use Asset, Amortization Interest on lease liabilities Finance Lease, Interest Expense Lease, Cost Lease, Cost Variable lease cost included within operating lease cost Variable Lease, Cost Income tax benefit on fair market value adjustment on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Income tax provision (benefit) on reclassification adjustment for net realized gain on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Schedule of Debt Schedule of Debt [Table Text Block] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Acquired software and technology Technology-Based Intangible Assets [Member] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Weighted-Average Useful Life Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Stock options excluded from the calculation of diluted weighted-average outstanding shares because their impact was anti-dilutive (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Business Segment Information Segment Reporting Disclosure [Text Block] Income Statement [Abstract] Processing and services Cost of revenue Cost of Goods and Services Sold Selling, general and administrative Selling, General and Administrative Expense (Gain) loss on sale of businesses Total expenses Costs and Expenses Operating income Interest expense, net Interest Income (Expense), Net Debt financing activities Other (expense) income Other Nonoperating Income (Expense) Income before income taxes and income from investments in unconsolidated affiliates Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax provision Income Tax Expense (Benefit) Income from investments in unconsolidated affiliates Net income Less: Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to Fiserv, Inc. Net Income (Loss) Attributable to Parent Net income attributable to Fiserv, Inc. per share – basic (in dollars per share) Earnings Per Share, Basic Net income attributable to Fiserv, Inc. per share – diluted (in dollars per share) Earnings Per Share, Diluted Shares used in computing net income per share: Basic (in shares) Diluted (in shares) Schedule of Funded Status of Defined Benefit Pension Plans Schedule of Net Funded Status [Table Text Block] Schedule of Weighted-Average Rate Assumptions Defined Benefit Plan, Assumptions [Table Text Block] Schedule of Expected Future Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Schedule of Components of Net Periodic Benefit Expense Schedule of Net Benefit Costs [Table Text Block] Increase (Decrease) in Temporary Equity [Roll Forward] Increase (Decrease) in Temporary Equity [Roll Forward] Beginning balance Acquired Temporary Equity, Stock Issued During Period, Value, New Issues Share of income Temporary Equity, Net Income Ending balance Income tax provision Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Schedule of total purchase price paid Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of purchase price allocation Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of gross carrying amount and weighted-average useful life allocated to intangible assets Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Schedule of Pro Forma Combined Financial Information Business Acquisition, Pro Forma Information [Table Text Block] Selling, General and Administrative Expenses Selling, General and Administrative Expenses [Member] Debt Financing Activities Debt Financing Activities [Member] Debt Financing Activities [Member] Common Shares Common Stock [Member] Number of shares issued for acquisition (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Goodwill, expected tax deductible amount Business Acquisition, Goodwill, Expected Tax Deductible Amount Number of entities to dispose Disposal Groups, Including Discontinued Operations, Number Of Entities Held For Sale Disposal Groups, Including Discontinued Operations, Number Of Entities Held For Sale Revenue of acquiree since acquisition date Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Impact to operating income (loss) of acquiree since acquisition date Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Transaction expenses incurred Business Combination, Acquisition Related Costs Payments for acquisitions of businesses Business Combination, Consideration Transferred Cash purchase price Payments to Acquire Businesses, Gross Working capital adjustments Business Combination, Consideration Transferred, Working Capital Adjustments Business Combination, Consideration Transferred, Working Capital Adjustments Future payments under a transition services agreement Business Combination, Liabilities Arising from Contingencies, Amount Recognized Decrease in goodwill Goodwill, Purchase Accounting Adjustments Transition services agreement term Business Combination, Liabilities Arising From Contingencies, Term Business Combination, Liabilities Arising From Contingencies, Term Acquired intangible asset amortization Amortization of Intangible Assets Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Banc of America Merchant Services Banc of America Merchant Services [Member] Banc of America Merchant Services [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Related Party Fees Related Party Fees [Member] Related Party Fees [Member] Merchant Alliances Equity Method Investee [Member] Joint Venture Corporate Joint Venture [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Processing, administrative, and other fees Revenue from Related Parties Amounts due from unconsolidated merchant alliances Due from Related Parties, Current Percentage of interest in joint venture Noncontrolling Interest, Ownership Percentage by Parent Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Equity securities Defined Benefit Plan, Equity Securities [Member] Debt securities Defined Benefit Plan, Debt Security [Member] Off-risk assets Defined Benefit Plan, Off Risk Assets [Member] Defined Benefit Plan, Off Risk Assets [Member] On-risk assets Defined Benefit Plan, On Risk Assets [Member] Defined Benefit Plan, On Risk Assets [Member] Expected contributions to defined contribution plans Defined Contribution Plan, Expected Future Employer Contributions, Current Fiscal Year Defined Contribution Plan, Expected Future Employer Contributions, Current Fiscal Year Plan assets target allocation percentage Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Number of plan asset investment pools Defined Benefit Plan, Plan Assets, Target Allocation, Number Of Investment Pools Defined Benefit Plan, Plan Assets, Target Allocation, Number Of Investment Pools Plan assets actual allocation percentage Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Expected contributions to defined benefit plans Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Computation of shares used in calculating basic and diluted net income per common share Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of intangible assets by class Schedule of Finite-Lived Intangible Assets [Table Text Block] Noncurrent assets Deferred Income Tax Assets, Net Noncurrent liabilities Total Deferred Tax Liabilities, Net Investments in Unconsolidated Affiliates Equity Method Investments and Joint Ventures Disclosure [Text Block] Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Geographic Concentration Risk Geographic Concentration Risk [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Foreign Tax Authority Foreign Tax Authority [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Sales Revenue, Net Revenue Benchmark [Member] Subsegment [Axis] Subsegments [Axis] Subsegment [Domain] Subsegments [Domain] Global Business Solutions Global Business Solutions Subsegment [Member] Global Business Solutions Subsegment [Member] Global Financial Solutions Global Financial Solutions Subsegment [Member] Global Financial Solutions Subsegment [Member] Network & Security Solutions Network And Security Solutions Subsegment [Member] Network And Security Solutions Subsegment [Member] Digital Money Movement Digital Money Movement Subsegment [Member] Digital Money Movement Subsegment [Member] Card and Related Services Card And Related Services Subsegment [Member] Card And Related Services Subsegment [Member] Other Payment And Industry Products Services, Other Subsegment [Member] Payment And Industry Products Services, Other Subsegment [Member] Account and Item Processing Account And Item Processing Subsegment [Member] Account And Item Processing Subsegment [Member] Lending Solutions Lending Solutions Subsegment [Member] Lending Solutions Subsegment [Member] Other Financial Institution Services, Other Subsegment [Member] Financial Institution Services, Other Subsegment [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Percentage of concentration risk Concentration Risk, Percentage Schedule of accounts payable and accrued expenses Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Performance Share Units Performance Shares [Member] Restricted Stock Awards Restricted Stock Awards [Member] Restricted Stock Awards [Member] Performance Share Awards Performance Stock Awards [Member] Performance Stock Awards [Member] Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Balance at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Converted First Data units/awards (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Conversion From Acquisition In Period Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Conversion From Acquisition In Period Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Balance at end of period (in shares) Weighted-Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Balance at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Converted First Data units/awards (in dollars per share) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Conversion From Acquisition In Period, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Conversion From Acquisition In Period, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Balance at end of period (in dollars per share) Revenue recognized which was included in the contract liability balance Contract with Customer, Liability, Revenue Recognized Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Discontinued Operations, Disposed of by Sale Discontinued Operations, Disposed of by Sale [Member] Discontinued Operations, Held-for-sale or Disposed of by Sale Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Consideration from sale of business Disposal Group, Including Discontinued Operation, Consideration Tax payment related to income recognized in 2017 from a prior disposition Discontinued Operation, Tax Effect of Income (Loss) from Discontinued Operation During Phase-out Period Assets held for sale Disposal Group, Including Discontinued Operation, Assets, Current Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Current Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Recently Adopted And Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Reserve for Merchant Credit Losses Loss Contingencies, Policy [Policy Text Block] Loss Contingencies, Policy [Policy Text Block] Derivatives Derivatives, Policy [Policy Text Block] Leasing Receivables Lessor, Leases [Policy Text Block] Pension Plans Pension and Other Postretirement Plans, Pensions, Policy [Policy Text Block] Settlement Assets and Obligations Settlement Assets And Obligations, Policy [Policy Text Block] Disclosure of accounting policy for settlement assets and obligations, including the policy for determination and quantification of balance(s). Net Income Per Share Earnings Per Share, Policy [Policy Text Block] Foreign Currency Foreign Currency Transactions and Translations Policy [Policy Text Block] Interest Expense, Net Interest Expense, Policy [Policy Text Block] Revenue from Contract with Customer Revenue from Contract with Customer [Policy Text Block] Acquisitions Business Combinations Policy [Policy Text Block] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Company as Lessee Lessee, Leases [Policy Text Block] Company as Lessor Business Acquisition, Pro Forma Information, Nonrecurring Adjustments [Table] Business Acquisition, Pro Forma Information, Nonrecurring Adjustments [Table] Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items] Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items] Total revenue Business Acquisition, Pro Forma Revenue Net income Business Acquisition, Pro Forma Net Income (Loss) Net income attributable to Fiserv, Inc. Business Acquisition, Pro Forma Income (Loss), Including Portion Attributable To Noncontrolling Interest Business Acquisition, Pro Forma Income (Loss), Including Portion Attributable To Noncontrolling Interest Net income per share attributable to Fiserv, Inc., Basic (in dollars per share) Business Acquisition, Pro Forma Earnings Per Share, Basic Net income per share attributable to Fiserv, Inc., Diluted (in dollars per share) Business Acquisition, Pro Forma Earnings Per Share, Diluted Accounts Payable and Accrued Expenses Accounts Payable and Accrued Liabilities Disclosure [Text Block] Schedule of Goodwill Schedule of Goodwill [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Cash Flow Hedges Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] Foreign Currency Translation Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Other Other Accumulated Other Comprehensive Income [Member] Accumulated change in equity from transactions and other events and circumstances from non-owner sources at fiscal year-end, not separately disclosed. Total AOCI Including Portion Attributable to Noncontrolling Interest [Member] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Principles, Early Adoption [Domain] New Accounting Principles, Early Adoption [Domain] New Accounting Pronouncement, Early Adoption, Effect New Accounting Pronouncement, Early Adoption, Effect [Member] Accounting Standards Update 2017-12 Accounting Standards Update 2017-12 [Member] Accounting Standards Update 2018-02 Accounting Standards Update 2018-02 [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Balance at beginning of period Other comprehensive loss before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive loss Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Cumulative-effect adjustment of ASU adoption Cumulative Effect of New Accounting Principle in Period of Adoption Balance at end of period Cash paid for amounts included in the measurement of lease liabilities Cash Flow, Lessee [Abstract] Cash Flow, Lessee [Abstract] Operating cash flows from operating leases Operating Lease, Payments Operating cash flows from finance leases Finance Lease, Interest Payment on Liability Financing cash flows from finance leases Finance Lease, Principal Payments Right-of-use assets obtained in exchange for lease liabilities Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract] Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract] Operating leases Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Finance leases Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Treasury Lock Treasury Lock [Member] Currency [Axis] Currency [Axis] All Currencies [Domain] All Currencies [Domain] Indian Rupee India, Rupees Notional amount of derivatives Derivative, Notional Amount Total fair value of cash flow hedge derivatives Cash Flow Hedges Derivative Instruments at Fair Value, Net Estimate of gain related to foreign currency exchange contracts during the next 12 months Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months Derivative liability, notional amount Derivative Liability, Notional Amount Estimated interest expense related to settled interest rate hedge contracts during the next twelve months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Foreign currency translation adjustment Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), After Reclassification And Tax Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), After Reclassification And Tax Cover page. Entities [Table] Entities [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Stock, par value $0.01 per share 0.375% Senior Notes due 2023 Senior Notes Due 2023 [Member] Senior Notes Due 2023 [Member] 1.125% Senior Notes due 2027 Senior Notes Due 2027 [Member] Senior Notes Due 2027 [Member] 1.625% Senior Notes due 2030 Senior Notes Due 2030 [Member] Senior Notes Due 2030 [Member] 2.250% Senior Notes due 2025 Senior Notes Due 2025 [Member] Senior Notes Due 2025 [Member] 3.000% Senior Notes due 2031 Senior Notes Due 2031 [Member] Senior Notes Due 2031 [Member] Entity Information [Line Items] Entity Information [Line Items] Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Assumptions Used to Determine Fair Value of Stock Options Assumed in Acquisition Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Assumptions Used to Determine Fair Value of Stock Options Granted Summary of Stock Option Activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Summary of Restricted Stock and Performance Activity Schedule Of Share-Based Compensation, Restricted Stock Units, Restricted Stock Awards, Performance Share Units And Performance Share Awards Activity [Table Text Block] Schedule Of Share-Based Compensation, Restricted Stock Units, Restricted Stock Awards, Performance Share Units And Performance Share Awards Activity [Table Text Block] Schedule of Additional Information Related to Stock Option and Restricted Stock Unit Activity Share-based Payment Arrangement, Activity [Table Text Block] Weighted-average remaining lease term Weighted Average Remaining Lease Term [Abstract] Weighted Average Remaining Lease Term [Abstract] Operating leases Operating Lease, Weighted Average Remaining Lease Term Finance leases Finance Lease, Weighted Average Remaining Lease Term Weighted-average discount rate Leases Weighted Average Discount Rate [Abstract] Leases Weighted Average Discount Rate [Abstract] Operating leases Operating Lease, Weighted Average Discount Rate, Percent Finance leases Finance Lease, Weighted Average Discount Rate, Percent Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Treasury Stock Treasury Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Noncontrolling Interests Noncontrolling Interest [Member] Class of Stock [Line Items] Class of Stock [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at beginning of period (in shares) Shares, Issued Shares issued to acquire First Data (see Note 4) (in shares) Stock Issued During Period, Shares, Acquisitions Shares issued to acquire First Data (see Note 4) Stock Issued During Period, Value, Acquisitions Shares issued to acquire First Data (see Note 4) Noncontrolling Interest, Increase from Business Combination Shares issued to acquire First Data (see Note 4) Stock Issued During Period, Value, Acquisitions, Including Portion Attributable to Noncontrolling Interest Stock Issued During Period, Value, Acquisitions, Including Portion Attributable to Noncontrolling Interest Distributions paid to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Net income Net Income (Loss), Including Portion Attributable To Nonreedemable Noncontrolling Interest Net Income (Loss), Including Portion Attributable To Nonreedemable Noncontrolling Interest Other comprehensive loss Share-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Shares issued under stock plans (in shares) Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Shares issued under stock plans Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Purchases of treasury stock (in shares) Treasury Stock, Shares, Acquired Purchases of treasury stock Treasury Stock, Value, Acquired, Cost Method Balance at end of period (in shares) Net income attributable to redeemable noncontrolling interest Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Stock options outstanding - balance at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Converted First Data stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Business Combination Share-based Compensation Arrangement by Share-based Payment Award, Options, Business Combination Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Exercised (in shares) Stock options outstanding - balance at end of period (in shares) Stock options exercisable (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted-Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Stock options outstanding - balance at beginning of period (in dollars per shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Converted First Data stock options (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Business Combination, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Business Combination, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Stock options outstanding - balance at end of period (in dollars per shares) Stock options exercisable (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Weighted Average Remaining Contractual Term, Stock options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Term, Stock options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value, Stock options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate Intrinsic Value, Stock options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Acquired intangible assets Acquired Intangible Assets [Member] Assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination. Capitalized and purchased software Capitalized And Purchased Software [Member] Purchased software applications and internally developed software for sale, licensing or long-term internal use (classified as intangible assets). Estimated annual amortization expense in 2019 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year Estimated annual amortization expense in 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated annual amortization expense in 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated annual amortization expense in 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated annual amortization expense in 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Five Goodwill Goodwill Disclosure [Text Block] Deferred tax liabilities Unrecognized tax benefits Unrecognized Tax Benefits Unrecognized tax benefits, increase from subsidiary restructuring Unrecognized Tax Benefits, Increase Resulting from Restructuring Activities Unrecognized Tax Benefits, Increase Resulting from Restructuring Activities Unrecognized tax benefits, increase from acquisition Unrecognized Tax Benefits, Increase Resulting from Acquisition Decrease in unrecognized tax benefits reasonably possible in next twelve months Decrease in Unrecognized Tax Benefits is Reasonably Possible Noncontrolling Interest [Table] Noncontrolling Interest [Table] First Data Joint Venture First Data Joint Venture [Member] First Data Joint Venture [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Ownership percentage by noncontrolling owner Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Termination of agreement notice (in months) Redeemable Noncontrolling Interest, Termination Notice Redeemable Noncontrolling Interest, Termination Notice Fair market value of minority interest's portfolio multiplication percentage Redeemable Noncontrolling Interest, Purchase Price, Multiplication Factor Percentage Redeemable Noncontrolling Interest, Purchase Price, Multiplication Factor Percentage Summary of Financial Information for Significant Unconsolidated Affiliates Accounted for Under the Equity Method Equity Method Investments [Table Text Block] Fair value of exchanges Total purchase price Share price of shares issued for acquisition (in dollars per share) Business Acquisition, Share Price Lessor, Lease, Description [Table] Lessor, Lease, Description [Table] Product revenue Sales [Member] Cost of product Cost of Sales [Member] Lessor, Lease, Description [Line Items] Lessor, Lease, Description [Line Items] Selling profit (charge) Sales-type and Direct Financing Leases, Profit (Loss) Interest income Sales-type and Direct Financing Leases, Interest Income Operating lease income Operating Lease, Lease Income Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes paid Income Taxes Paid, Net Treasury stock purchases settled after the balance sheet date Treasury Stock Purchases Settled After Balance Sheet Date Future cash outflow to pay for treasury stock purchases that have occurred. Total intrinsic value of stock options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Fair value of restricted stock units vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Income tax benefit from stock options exercised and restricted stock units vested Employee Service Share-based Compensation Tax Benefit Realized From Exercise Of Stock Options And Vesting Of Restricted Stock Units Employee Service Share-based Compensation Tax Benefit Realized From Exercise Of Stock Options And Vesting Of Restricted Stock Units Cash received from stock options exercised Proceeds from Stock Options Exercised