Accounting Policies (Policies)	6 Months Ended
Accounting Policies (Policies)	Sep. 30, 2016
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 in accordance 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, 2016 (2016 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 six months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the fiscal year ending March 31, 2017.
Divestitures	Divestitures: In the fourth quarter of fiscal year 2016, the Company sold its CA ERwin Data Modeling solution assets (ERwin). The results of operations associated with this business have been presented as discontinued operations in the accompanying Condensed Consolidated Statements of Operations for the three and six months ended September 30, 2015 and Condensed Consolidated Statements of Cash Flows for the six months ended September 30, 2015.
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 83% being held by the Company’s foreign subsidiaries outside the United States at September 30, 2016.
New Accounting Pronouncements	New Accounting Pronouncements: In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers, which creates new ASC Topic 606 (Topic 606) that 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. In March 2016, April 2016 and May 2016, the FASB issued additional amendments to the technical guidance of Topic 606. Topic 606 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. 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 currently evaluating the effect that this guidance will have on its consolidated financial statements and related disclosures. Topic 606 is expected to have a significant effect on the Company’s revenue recognition policies and disclosures. The Company has not yet selected a transition method nor has it determined the effect the standard will have on its ongoing financial reporting. In February 2016, the FASB issued Accounting Standards Update No. 2016-02 (ASU 2016-02), Leases (Topic 842), which requires a lessee to recognize assets and liabilities on its consolidated balance sheet for leases with accounting lease terms of more than 12 months. ASU 2016-02 will replace most existing lease accounting guidance in U.S. GAAP when it becomes effective. The new standard states that a lessee will recognize a lease liability for the obligation to make lease payments and a right-of-use asset for the right to use the underlying asset for the lease term. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the consolidated statements of operations. ASU 2016-02 will be effective for the Company’s first quarter of fiscal year 2020 and requires the modified retrospective method of adoption. Early adoption is permitted. Although the Company is currently evaluating the effect that ASU 2016-02 will have on its consolidated financial statements and related disclosures, the Company expects that most of its operating lease commitments will be subject to the new standard and recognized as operating lease liabilities and right-of-use assets upon adoption. In March 2016, the FASB issued Accounting Standards Update No. 2016-09 (ASU 2016-09), Improvements to Employee Share-Based Payment Accounting (Topic 718), which is intended to simplify several aspects of the accounting for share-based payment award transactions, including the income tax consequences and classification on the statement of cash flows. ASU 2016-09 will be effective for the Company’s first quarter of fiscal year 2018 and early adoption is permitted. The Company is currently evaluating the guidance to determine the adoption methods and the effect that ASU 2016-09 will have on its consolidated financial statements and related disclosures. In August 2016, the FASB issued Accounting Standards Update No. 2016-15 (ASU 2016-15), Classification of Certain Cash Receipts and Cash Payments (Topic 230), which is intended to reduce diversity in practice on how certain cash receipts and cash payments are presented and classified in the statement of cash flows. ASU 2016-15 will be effective for the Company’s first quarter of fiscal year 2019 and requires a retrospective transition method of adoption. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material effect on its consolidated financial statements and related disclosures. In October 2016, the FASB issued Accounting Standards Update No. 2016-16 (ASU 2016-16), Intra-Equity Transfers of Assets Other Than Inventory (Topic 740), which is intended to eliminate diversity in practice and provide a more accurate depiction of the tax consequences on intercompany asset transfers (excluding inventory). ASU 2016-16 requires entities to immediately recognize the tax consequences on intercompany asset transfers (excluding inventory) at the transaction date, rather than deferring the tax consequences under current GAAP. ASU 2016-16 will be effective for the Company’s first quarter of fiscal year 2019 and requires a modified retrospective method of adoption. Early adoption is permitted, but only in the first quarter of an entity’s annual fiscal year. The Company is currently evaluating the effect that ASU 2016-16 will have on its consolidated financial statements and related disclosures.

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.