Summary of Accounting Policies	9 Months Ended
Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Accounting Policies	Summary of Accounting Policies The Condensed Consolidated Financial Statements of DST Systems, Inc. and consolidated subsidiaries (“we,” “our,” “us,” the “Company” or “DST”) included herein have been prepared by the Company, without audit, pursuant to the rules and regulations of the United States Securities and Exchange Commission. Certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although we believe that the disclosures are adequate to enable a reasonable understanding of the information presented. These Condensed Consolidated Financial Statements should be read in conjunction with our audited financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. In March 2017, we acquired State Street Corporation’s (“State Street”) ownership in both Boston Financial Data Services, Inc. (“BFDS”) and International Financial Data Services Limited (“IFDS U.K.”), which resulted in control of the entities. As such, they were consolidated in our financial results from the date control was obtained. In addition, beginning in 2017, DST established a new reportable segment structure that separates the previously reported Financial Services segment into two new segments, Domestic Financial Services and International Financial Services, based upon the geographical location of the revenue-generating business. The activity within the previously reported Investments and Other segment has now been included in either the Domestic or International Financial Services segments based on the business supported. The Healthcare Services segment remains unchanged. The new segment presentation is reflective of how management is now operating the business and making resource allocations following the acquisitions of the remaining interests in IFDS U.K. and BFDS in the first quarter 2017, as well as the recent reductions in non-core investment assets resulting from monetizations and the use of State Street stock in the BFDS exchange transaction. The Company’s operating business units are now reported as three operating segments (Domestic Financial Services, International Financial Services and Healthcare Services). Certain amounts in the 2016 financial statements have been reclassified to conform to the 2017 presentation and prior periods have been revised to reflect the new reportable operating segments. In May 2017, our Board of Directors declared a two-for-one stock split of DST’s outstanding common stock effected in the form of a stock dividend, which was paid on June 8, 2017 to shareholders of record at the close of business on May 26, 2017. In connection with the stock split, 16.5 million treasury shares were used to settle a portion of the distribution. All share and per share data, excluding treasury shares, have been retroactively adjusted for all periods presented to reflect the stock split as if the stock split had occurred at the beginning of the earliest period presented. In the opinion of management, the accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments (consisting only of normal recurring adjustments) necessary to fairly state the consolidated financial position and the results of operations, comprehensive income, changes in stockholders’ equity and cash flows for the periods presented. The results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results to be expected for the full year 2017. Recently Adopted Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued guidance which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. The guidance was adopted by us on January 1, 2017 and resulted in approximately $0.6 million and $2.6 million of excess tax benefits being recognized in Income taxes in the Condensed Consolidated Statement of Income for the three and nine months ended September 30, 2017, respectively. We also elected to account for forfeitures as they occur rather than using an estimated forfeiture rate. The impact to our consolidated financial statements was not material. Accounting Pronouncements Pending Adoption In November 2016, the FASB issued guidance which requires the statement of cash flows to explain changes during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The guidance is effective January 1, 2018 and requires retrospective application. Early adoption is permitted. We are currently evaluating the standard and the impact it will have on our consolidated financial statements, but have determined that our Funds held on behalf of clients and Other assets that meet the definition of cash and cash equivalents but are restricted for use will be included when reconciling the beginning and end of period balances on the Condensed Consolidated Statement of Cash Flows. In October 2016, the FASB issued guidance which requires the recognition of income tax consequences for intra-entity transfers of assets other than inventory. The guidance is effective January 1, 2018 and requires modified retrospective application. Early adoption is permitted. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures, however we do not expect it to have a material impact on our consolidated financial statements. In February 2016, the FASB issued guidance which requires lessees to reflect most leases on their balance sheet as assets and obligations. The guidance is effective January 1, 2019 with early adoption permitted. The standard is to be applied under the modified retrospective method, with elective reliefs, which requires application of the new guidance for all periods presented. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures. In January 2016, the FASB issued guidance which updates the reporting model for certain financial instruments, including the requirement for equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. The guidance is effective January 1, 2018 and requires a cumulative-effective adjustment as of the beginning of the fiscal year of adoption. Early adoption is permitted as of the beginning of the fiscal year of adoption. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures, but generally believe our private equity funds accounted for under the cost method will be measured at fair value, resulting in increased volatility in our Condensed Consolidated Statement of Income. In May 2014, the FASB issued guidance which requires companies to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration it expects to be entitled in exchange for those goods or services. The new standard and subsequently issued amendments will become effective January 1, 2018. We plan to adopt the guidance using the modified retrospective transition approach. We are currently evaluating the impacts of the application of the new standard to our existing portfolio of customer contracts and will continue to review new contracts entered into prior to the adoption of the new standard. While we expect the adoption of the standard will change the timing of when revenue is recognized for certain revenue streams, we currently anticipate that the majority of our contracts with customers that include account- and/or transaction-based processing fees will be accounted for under the series deliverable guidance in the new standard which will likely result in minimal changes as compared to current revenue recognition. These revenues will continue to be recognized over time as a single stand-ready performance obligation. As such, we do not currently anticipate significant changes in current systems or processes. Although we currently do not believe there will be a material impact of adopting the new revenue standard on our consolidated financial statements, our assessment of the expected impact of adoption will continue throughout the remainder of 2017.

Summary of Accounting Policies

The Condensed Consolidated Financial Statements of DST Systems, Inc. and consolidated subsidiaries (“we,” “our,” “us,” the “Company” or “DST”) included herein have been prepared by the Company, without audit, pursuant to the rules and regulations of the United States Securities and Exchange Commission. Certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although we believe that the disclosures are adequate to enable a reasonable understanding of the information presented. These Condensed Consolidated Financial Statements should be read in conjunction with our audited financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016.

In March 2017, we acquired State Street Corporation’s (“State Street”) ownership in both Boston Financial Data Services, Inc. (“BFDS”) and International Financial Data Services Limited (“IFDS U.K.”), which resulted in control of the entities. As such, they were consolidated in our financial results from the date control was obtained.

In addition, beginning in 2017, DST established a new reportable segment structure that separates the previously reported Financial Services segment into two new segments, Domestic Financial Services and International Financial Services, based upon the geographical location of the revenue-generating business. The activity within the previously reported Investments and Other segment has now been included in either the Domestic or International Financial Services segments based on the business supported. The Healthcare Services segment remains unchanged. The new segment presentation is reflective of how management is now operating the business and making resource allocations following the acquisitions of the remaining interests in IFDS U.K. and BFDS in the first quarter 2017, as well as the recent reductions in non-core investment assets resulting from monetizations and the use of State Street stock in the BFDS exchange transaction. The Company’s operating business units are now reported as three operating segments (Domestic Financial Services, International Financial Services and Healthcare Services). Certain amounts in the 2016 financial statements have been reclassified to conform to the 2017 presentation and prior periods have been revised to reflect the new reportable operating segments.

In May 2017, our Board of Directors declared a two-for-one stock split of DST’s outstanding common stock effected in the form of a stock dividend, which was paid on June 8, 2017 to shareholders of record at the close of business on May 26, 2017. In connection with the stock split, 16.5 million treasury shares were used to settle a portion of the distribution. All share and per share data, excluding treasury shares, have been retroactively adjusted for all periods presented to reflect the stock split as if the stock split had occurred at the beginning of the earliest period presented.

In the opinion of management, the accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments (consisting only of normal recurring adjustments) necessary to fairly state the consolidated financial position and the results of operations, comprehensive income, changes in stockholders’ equity and cash flows for the periods presented. The results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results to be expected for the full year 2017.

Recently Adopted Accounting Pronouncements

In March 2016, the Financial Accounting Standards Board (“FASB”) issued guidance which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. The guidance was adopted by us on January 1, 2017 and resulted in approximately $0.6 million and $2.6 million of excess tax benefits being recognized in Income taxes in the Condensed Consolidated Statement of Income for the three and nine months ended September 30, 2017, respectively. We also elected to account for forfeitures as they occur rather than using an estimated forfeiture rate. The impact to our consolidated financial statements was not material.

Accounting Pronouncements Pending Adoption

In November 2016, the FASB issued guidance which requires the statement of cash flows to explain changes during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The guidance is effective January 1, 2018 and requires retrospective application. Early adoption is permitted. We are currently evaluating the standard and the impact it will have on our consolidated financial statements, but have determined that our Funds held on behalf of clients and Other assets that meet the definition of cash and cash equivalents but are restricted for use will be included when reconciling the beginning and end of period balances on the Condensed Consolidated Statement of Cash Flows.

In October 2016, the FASB issued guidance which requires the recognition of income tax consequences for intra-entity transfers of assets other than inventory. The guidance is effective January 1, 2018 and requires modified retrospective application. Early adoption is permitted. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures, however we do not expect it to have a material impact on our consolidated financial statements.

In February 2016, the FASB issued guidance which requires lessees to reflect most leases on their balance sheet as assets and obligations. The guidance is effective January 1, 2019 with early adoption permitted. The standard is to be applied under the modified retrospective method, with elective reliefs, which requires application of the new guidance for all periods presented. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures.

In January 2016, the FASB issued guidance which updates the reporting model for certain financial instruments, including the requirement for equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. The guidance is effective January 1, 2018 and requires a cumulative-effective adjustment as of the beginning of the fiscal year of adoption. Early adoption is permitted as of the beginning of the fiscal year of adoption. We are currently evaluating the standard and the impact it will have on our consolidated financial statements and related disclosures, but generally believe our private equity funds accounted for under the cost method will be measured at fair value, resulting in increased volatility in our Condensed Consolidated Statement of Income.

In May 2014, the FASB issued guidance which requires companies to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration it expects to be entitled in exchange for those goods or services. The new standard and subsequently issued amendments will become effective January 1, 2018. We plan to adopt the guidance using the modified retrospective transition approach. We are currently evaluating the impacts of the application of the new standard to our existing portfolio of customer contracts and will continue to review new contracts entered into prior to the adoption of the new standard. While we expect the adoption of the standard will change the timing of when revenue is recognized for certain revenue streams, we currently anticipate that the majority of our contracts with customers that include account- and/or transaction-based processing fees will be accounted for under the series deliverable guidance in the new standard which will likely result in minimal changes as compared to current revenue recognition. These revenues will continue to be recognized over time as a single stand-ready performance obligation. As such, we do not currently anticipate significant changes in current systems or processes. Although we currently do not believe there will be a material impact of adopting the new revenue standard on our consolidated financial statements, our assessment of the expected impact of adoption will continue throughout the remainder of 2017.