Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenue and expenses during the period reported. Actual results could differ from those estimates.
Subsequent Events, Policy [Policy Text Block]	Evaluation of Subsequent Events The Company evaluated subsequent events through the date that our Condensed Consolidated Financial Statements were issued. Except as described below, no matters were identified that required adjustment of the Condensed Consolidated Financial Statements or additional disclosure. Planned Acquisition of JetPay Corporation On October 19, 2018, we entered into an Agreement and Plan of Merger (the “Merger Agreement”) with JetPay Corporation (“JetPay”), a provider of end-to-end payment processing and human capital management solutions, pursuant to which NCR agreed to purchase all of the outstanding shares of common stock of JetPay through a cash tender offer at a price per share of $5.05 for a total value of approximately $184 million. NCR plans to finance the acquisition through existing cash and existing capacity under its revolving credit facility. The transaction has been approved by the Board of Directors of each company. The transaction, which is subject to approval by regulatory authorities and other customary closing conditions, is currently expected to close by the end of the fourth quarter of 2018. However, it is possible that factors outside of our control could require us to complete the transaction at a later time or not at all.
Reclassifications	Reclassifications Certain prior-period amounts have been reclassified in the accompanying Condensed Consolidated Financial Statements and Notes thereto in order to conform to the current period presentation.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Issued In February 2016, the Financial Accounting Standards Board (FASB) issued a new leasing standard that will supersede current guidance related to accounting for leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The standard will be effective for the first interim period within annual periods beginning after December 15, 2018, with early adoption permitted. The standard is required to be adopted using the modified retrospective approach and NCR plans to apply the provisions of the new leasing standard at the effective date rather than at the beginning of the earliest period presented under the transition method provided. The standard also includes options to elect a number of practical expedients. We plan on electing the package of practical expedients to not reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs and are evaluating the remaining practical expedients available under the guidance. As part of the adoption of the standard, we have selected and are in the process of implementing new lease accounting software. We are also in the process of identifying and designing appropriate changes to our business processes, systems and controls to support the new standard, and we are continuing to evaluate the impact of the standard on our consolidated financial statements and related disclosures. At this time the Company cannot estimate the quantitative impact of adopting the new standard, but it is expected to have a material effect to the total assets and total liabilities reported on the consolidated balance sheet, and is not expected to have a material effect to the consolidated statement of operations or the consolidated statement of cash flows. In August 2018, the FASB issued an accounting standard update which require additional disclosures related to the weighted-average interest crediting rates for cash balance plans and an explanation for the reasons for significant gains and losses related to changes in the benefit obligation for the period. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020 on a retrospective basis with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements. In August 2018, the FASB issued an accounting standard update with new guidance on fair value measurement disclosure requirements which requires the disclosure of additions to and transfers into and out of Level 3 of the fair value hierarchy. The update also requires disclosure about the uncertainty in measurement as of the reporting date. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019 with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements. In August 2018, the FASB issued additional guidance for an accounting update that was issued in April 2015 related to accounting for implementation costs incurred in a cloud computing arrangement that is also a service contract. If a cloud computing arrangement also includes an internal-use software, an intangible asset is recognized and a liability is recognized for any payments related to the software license. However, if a cloud computing arrangement does not include a software license, the entity should account for the arrangement as a service contract and any fees associated with the service are expensed as incurred. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements. In October 2018, the FASB issued an accounting standards update for hedge accounting guidance that was issued in August 2017 which we adopted during the first quarter of the this year. This guidance allows for the use of a broad Treasury repurchase agreement financing rate which is referred to as the Secured Overnight Financing Rate (SOFR) to be used as an additional benchmark rate for hedge accounting purposes. This guidance is effective for entities that have already adopted the amendments of the hedge accounting guidance referenced above for fiscal years beginning after December 15, 2018 on a prospective basis for qualifying new or re-designated hedging relationships entered into on or after the date of adoption. The adoption of this accounting standard update is not expected to have a material effect on our consolidated financial statements. Adopted In May 2014, the FASB issued a new revenue recognition standard that superseded existing revenue recognition guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard was effective for the first interim period within annual periods beginning after December 15, 2017, with early adoption permitted for annual periods beginning after December 15, 2016, and can be adopted either retrospectively to each prior reporting period presented (“full retrospective method”) or as a cumulative effect adjustment as of the date of adoption (“modified retrospective method”). Effective January 1, 2018, we adopted the standard using the modified retrospective method applied to contracts that were not complete as of the date of adoption and recorded a cumulative adjustment to increase retained earnings by $2 million. Adoption of the new standard resulted in changes to our accounting policies for revenue recognition and deferred commissions. Refer to Note 2. Accounting Policies related to Revenue with Contracts with Customers, for the updated policy disclosures, and Note 3. Revenue Recognized under Previous Guidance, for presentation of what revenue would have been in the current periods had the Company continued to recognize revenue under the previous accounting guidance. In August 2016, the FASB issued an accounting standards update which provides guidance regarding the classification of certain cash receipts and cash payments on the statement of cash flows, where specific guidance is provided for issues not previously addressed. This guidance is effective for annual reporting periods, including interim reporting within those periods, beginning after December 15, 2017, with early adoption permitted, and is required to be adopted using a retrospective approach. The adoption of this accounting standards update did not have a material effect on the Company's statement of cash flows. In October 2016, the FASB issued an accounting standards update which requires the recognition of the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. This standard is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted. Effective January 1, 2018, we adopted the standard using the modified retrospective method and recorded a cumulative adjustment to increase retained earnings by $13 million. In November 2016, the FASB issued an accounting standards update which clarifies how entities should present restricted cash and restricted cash equivalents in the statement of cash flows. The guidance requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. The accounting standards update is required to be adopted for annual periods beginning after December 15, 2017, including interim periods within that annual period. The amendment is to be applied retrospectively with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's statement of cash flows. In January 2017, the FASB issued an accounting standards update which clarifies the definition of a business which is used across several areas of accounting. The area expected to see the most change is the evaluation of whether a transaction should be accounted for as an acquisition (or disposal) of assets, or as a business combination. The new guidance clarifies that to be a business there must also be at least one substantive process, and narrows the definition of outputs by more closely aligning it with how outputs are described in the new revenue recognition standard. The accounting standards update is required to be adopted for annual periods beginning after December 15, 2017, including interim periods within that annual period. The amendment is to be applied prospectively with early adoption permitted. The adoption of this standard did not have a material effect on our financial condition, results of operations or disclosures, as the standard applies only to businesses acquired after the adoption date. In January 2017, the FASB issued an accounting standards update with new guidance intended to simplify the subsequent measurement of goodwill. The standards update eliminates the requirement for an entity to calculate the implied fair value of goodwill to measure a goodwill impairment charge. Instead, an entity will perform its annual, or interim, goodwill impairment testing by comparing the fair value of a reporting unit with its carrying amount and recording an impairment charge for the amount by which the carrying amount exceeds the fair value. The standards update is effective prospectively for annual and interim goodwill impairment testing performed in fiscal years beginning after December 15, 2019, which we early adopted as of January 1, 2018. Refer to Note 4. Goodwill and Long-Lived Assets for further discussion. In March 2017, the FASB issued an accounting standards update with new guidance on an employer's presentation of defined benefit retirement costs in the income statement. Employers will present the service cost component of net periodic benefit cost in the same income statement line item(s) as other employee compensation costs arising from services rendered during the period. Only the service cost component will be eligible for capitalization in assets. Employers will present the other components of the net periodic benefit cost separately from the line item(s) that includes the service cost and outside of any subtotal of operating income, if one is presented. These components will not be eligible for capitalization in assets. The guidance is effective for fiscal years beginning after December 15, 2017, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition. In May 2017, the FASB issued an accounting standards update which clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. This update requires modification only if the fair value, vesting conditions or the classification of the award changes as a result of the change in terms or conditions. This guidance is effective for fiscal years beginning after December 15, 2017, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition. In August 2017, the FASB issued an accounting standards update which simplifies certain aspects of hedge accounting and improves disclosures of hedging arrangements through the elimination of the requirement to separately measure and report hedge ineffectiveness. This update generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item in order to align financial reporting of hedge relationships with economic results. Entities must apply the amendments to cash flow and net investment hedge relationships that exist on the date of adoption using a modified retrospective approach. The presentation and disclosure requirements must be applied prospectively. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition. In February 2018, the FASB issued an accounting standards update which permits entities to reclassify tax effects stranded in accumulated other comprehensive income as a result of the enactment of the Tax Cuts and Jobs Act (U.S. Tax Reform) to retained earnings. Entities can elect to apply the guidance retrospectively or in the period of adoption. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition. In March 2018, the FASB issued an accounting standards update which allowed SEC registrants to record provisional amounts in earnings for the year ended December 31, 2017 due to the complexities involved in accounting for the enactment of U.S. Tax Reform. The standard was effective upon issuance. The Company recognized the estimated income tax effects of U.S. Tax Reform in its 2017 Consolidated Financial Statements in accordance with SEC Staff Accounting Bulletin No. 118 (SAB No. 118). Refer to Note 6. Income Taxes, for further information regarding the provisional amounts recorded by the Company as of December 31, 2017.

Recent Accounting Pronouncements

Issued

In February 2016, the Financial Accounting Standards Board (FASB) issued a new leasing standard that will supersede current guidance related to accounting for leases. The guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The standard will be effective for the first interim period within annual periods beginning after December 15, 2018, with early adoption permitted. The standard is required to be adopted using the modified retrospective approach and NCR plans to apply the provisions of the new leasing standard at the effective date rather than at the beginning of the earliest period presented under the transition method provided. The standard also includes options to elect a number of practical expedients. We plan on electing the package of practical expedients to not reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs and are evaluating the remaining practical expedients available under the guidance. As part of the adoption of the standard, we have selected and are in the process of implementing new lease accounting software. We are also in the process of identifying and designing appropriate changes to our business processes, systems and controls to support the new standard, and we are continuing to evaluate the impact of the standard on our consolidated financial statements and related disclosures. At this time the Company cannot estimate the quantitative impact of adopting the new standard, but it is expected to have a material effect to the total assets and total liabilities reported on the consolidated balance sheet, and is not expected to have a material effect to the consolidated statement of operations or the consolidated statement of cash flows.

In August 2018, the FASB issued an accounting standard update which require additional disclosures related to the weighted-average interest crediting rates for cash balance plans and an explanation for the reasons for significant gains and losses related to changes in the benefit obligation for the period. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020 on a retrospective basis with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements.

In August 2018, the FASB issued an accounting standard update with new guidance on fair value measurement disclosure requirements which requires the disclosure of additions to and transfers into and out of Level 3 of the fair value hierarchy. The update also requires disclosure about the uncertainty in measurement as of the reporting date. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019 with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements.

In August 2018, the FASB issued additional guidance for an accounting update that was issued in April 2015 related to accounting for implementation costs incurred in a cloud computing arrangement that is also a service contract. If a cloud computing arrangement also includes an internal-use software, an intangible asset is recognized and a liability is recognized for any payments related to the software license. However, if a cloud computing arrangement does not include a software license, the entity should account for the arrangement as a service contract and any fees associated with the service are expensed as incurred. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. The impact of adopting this guidance is not expected to have a material impact on our consolidated financial statements.

In October 2018, the FASB issued an accounting standards update for hedge accounting guidance that was issued in August 2017 which we adopted during the first quarter of the this year. This guidance allows for the use of a broad Treasury repurchase agreement financing rate which is referred to as the Secured Overnight Financing Rate (SOFR) to be used as an additional benchmark rate for hedge accounting purposes. This guidance is effective for entities that have already adopted the amendments of the hedge accounting guidance referenced above for fiscal years beginning after December 15, 2018 on a prospective basis for qualifying new or re-designated hedging relationships entered into on or after the date of adoption. The adoption of this accounting standard update is not expected to have a material effect on our consolidated financial statements.

Adopted

In May 2014, the FASB issued a new revenue recognition standard that superseded existing revenue recognition guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard was effective for the first interim period within annual periods beginning after December 15, 2017, with early adoption permitted for annual periods beginning after December 15, 2016, and can be adopted either retrospectively to each prior reporting period presented (“full retrospective method”) or as a cumulative effect adjustment as of the date of adoption (“modified retrospective method”). Effective January 1, 2018, we adopted the standard using the modified retrospective method applied to contracts that were not complete as of the date of adoption and recorded a cumulative adjustment to increase retained earnings by $2 million. Adoption of the new standard resulted in changes to our accounting policies for revenue recognition and deferred commissions. Refer to Note 2. Accounting Policies related to Revenue with Contracts with Customers, for the updated policy disclosures, and Note 3. Revenue Recognized under Previous Guidance, for presentation of what revenue would have been in the current periods had the Company continued to recognize revenue under the previous accounting guidance.

In August 2016, the FASB issued an accounting standards update which provides guidance regarding the classification of certain cash receipts and cash payments on the statement of cash flows, where specific guidance is provided for issues not previously addressed. This guidance is effective for annual reporting periods, including interim reporting within those periods, beginning after December 15, 2017, with early adoption permitted, and is required to be adopted using a retrospective approach. The adoption of this accounting standards update did not have a material effect on the Company's statement of cash flows.

In October 2016, the FASB issued an accounting standards update which requires the recognition of the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. This standard is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted. Effective January 1, 2018, we adopted the standard using the modified retrospective method and recorded a cumulative adjustment to increase retained earnings by $13 million.

In November 2016, the FASB issued an accounting standards update which clarifies how entities should present restricted cash and restricted cash equivalents in the statement of cash flows. The guidance requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. The accounting standards update is required to be adopted for annual periods beginning after December 15, 2017, including interim periods within that annual period. The amendment is to be applied retrospectively with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's statement of cash flows.

In January 2017, the FASB issued an accounting standards update which clarifies the definition of a business which is used across several areas of accounting. The area expected to see the most change is the evaluation of whether a transaction should be accounted for as an acquisition (or disposal) of assets, or as a business combination. The new guidance clarifies that to be a business there must also be at least one substantive process, and narrows the definition of outputs by more closely aligning it with how outputs are described in the new revenue recognition standard. The accounting standards update is required to be adopted for annual periods beginning after December 15, 2017, including interim periods within that annual period. The amendment is to be applied prospectively with early adoption permitted. The adoption of this standard did not have a material effect on our financial condition, results of operations or disclosures, as the standard applies only to businesses acquired after the adoption date.

In January 2017, the FASB issued an accounting standards update with new guidance intended to simplify the subsequent measurement of goodwill. The standards update eliminates the requirement for an entity to calculate the implied fair value of goodwill to measure a goodwill impairment charge. Instead, an entity will perform its annual, or interim, goodwill impairment testing by comparing the fair value of a reporting unit with its carrying amount and recording an impairment charge for the amount by which the carrying amount exceeds the fair value. The standards update is effective prospectively for annual and interim goodwill impairment testing performed in fiscal years beginning after December 15, 2019, which we early adopted as of January 1, 2018. Refer to Note 4. Goodwill and Long-Lived Assets for further discussion.

In March 2017, the FASB issued an accounting standards update with new guidance on an employer's presentation of defined benefit retirement costs in the income statement. Employers will present the service cost component of net periodic benefit cost in the same income statement line item(s) as other employee compensation costs arising from services rendered during the period. Only the service cost component will be eligible for capitalization in assets. Employers will present the other components of the net periodic benefit cost separately from the line item(s) that includes the service cost and outside of any subtotal of operating income, if one is presented. These components will not be eligible for capitalization in assets. The guidance is effective for fiscal years beginning after December 15, 2017, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition.

In May 2017, the FASB issued an accounting standards update which clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. This update requires modification only if the fair value, vesting conditions or the classification of the award changes as a result of the change in terms or conditions. This guidance is effective for fiscal years beginning after December 15, 2017, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition.

In August 2017, the FASB issued an accounting standards update which simplifies certain aspects of hedge accounting and improves disclosures of hedging arrangements through the elimination of the requirement to separately measure and report hedge ineffectiveness. This update generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item in order to align financial reporting of hedge relationships with economic results. Entities must apply the amendments to cash flow and net investment hedge relationships that exist on the date of adoption using a modified retrospective approach. The presentation and disclosure requirements must be applied prospectively. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition.

In February 2018, the FASB issued an accounting standards update which permits entities to reclassify tax effects stranded in accumulated other comprehensive income as a result of the enactment of the Tax Cuts and Jobs Act (U.S. Tax Reform) to retained earnings. Entities can elect to apply the guidance retrospectively or in the period of adoption. This guidance is effective for fiscal years beginning after December 15, 2018, and interim periods therein, with early adoption permitted. The adoption of this accounting standards update did not have a material effect on the Company's net income, cash flows or financial condition.

In March 2018, the FASB issued an accounting standards update which allowed SEC registrants to record provisional amounts in earnings for the year ended December 31, 2017 due to the complexities involved in accounting for the enactment of U.S. Tax Reform. The standard was effective upon issuance. The Company recognized the estimated income tax effects of U.S. Tax Reform in its 2017 Consolidated Financial Statements in accordance with SEC Staff Accounting Bulletin No. 118 (SAB No. 118). Refer to Note 6. Income Taxes, for further information regarding the provisional amounts recorded by the Company as of December 31, 2017.