Accounting Policies (Policies)	9 Months Ended
Accounting Policies (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying unaudited Condensed Consolidated Financial Statements of CA, Inc. (Company) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP), as defined in Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 270, for interim financial information and with the instructions to Rule 10-01 of Securities and Exchange Commission Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. For further information, refer to the Company’s Consolidated Financial Statements and Notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2015 (2015 Form 10-K). In the opinion of management, all adjustments considered necessary for a fair presentation have been included. All such adjustments are of a normal, recurring nature. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Although these estimates are based on management’s knowledge of current events and actions it may undertake in the future, these estimates may ultimately differ from actual results. Operating results for the three and nine months ended December 31, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending March 31, 2016.
Divestitures	Divestitures: In the second quarter of fiscal year 2015, the Company sold its CA arcserve data protection solution assets (arcserve). In the fourth quarter of fiscal year 2014, the Company identified its CA ERwin Data Modeling solution assets (ERwin) as available for sale. The results of operations associated with these businesses have been presented as discontinued operations in the accompanying Condensed Consolidated Statements of Operations and Condensed Consolidated Statements of Cash Flows. The effects of the discontinued operations were immaterial to the Company’s Condensed Consolidated Balance Sheets at December 31, 2015 and March 31, 2015. See Note C, “Divestitures,” for additional information.
Cash and Cash Equivalents	Cash and Cash Equivalents: The Company’s cash and cash equivalents are held in numerous locations throughout the world, with approximately 84% being held by the Company’s foreign subsidiaries outside the United States at December 31, 2015.
New Accounting Pronouncements	New Accounting Pronouncements: In May 2014, the FASB issued Accounting Standards Update No. 2014-09 (ASU 2014-09), Revenue from Contracts with Customers (Topic 606), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In July 2015, the FASB issued a one-year deferral of the effective date of the new revenue recognition standard. The new standard will be effective for the Company's first quarter of fiscal year 2019 and early application for fiscal year 2018 is permitted. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. ASU 2014-09 is expected to have a significant impact on the Company’s revenue recognition policies and disclosures. The Company has not yet selected a transition method nor has it determined when it will adopt the standard and the effect of the standard on its ongoing financial reporting. In April 2015, the FASB issued Accounting Standards Update No. 2015-03 (ASU 2015-03), Simplifying the Presentation of Debt Issuance Costs (Topic 835), which changes the required presentation of debt issuance costs from an asset on the balance sheet to a deduction from the related debt liability. This guidance will be effective for the Company in its first quarter of fiscal year 2017 and early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company's consolidated financial statements. In November 2015, the FASB issued Accounting Standards Update No. 2015-17 (ASU 2015-17), Balance Sheet Classification of Deferred Taxes (Topic 740), to simplify the presentation of deferred taxes in the statement of financial position. The updated guidance requires that deferred tax assets and liabilities be classified as non-current in the consolidated balance sheets. The standard will be effective for the Company’s first quarter of fiscal year 2018 and early adoption is permitted. This guidance may be applied either prospectively to all deferred tax assets and liabilities, or retrospectively to all periods presented. The Company is currently in the process of assessing the impact on its consolidated financial statements and evaluating the adoption methods.

Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.