Recent Accounting Pronouncements (Policies)	9 Months Ended
Dec. 30, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Basis of presentation	Computer Sciences Corporation (CSC or the Company) has prepared the interim unaudited Condensed Consolidated Financial Statements included herein pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (SEC) for quarterly reports and, therefore, such financial statements omit or condense certain note disclosures and other information required by generally accepted accounting principles in the United States (GAAP) for complete financial statements. These financial statements should therefore be read in conjunction with the audited Consolidated Financial Statements and accompanying Notes included in the Company's Annual Report on Form 10-K for the fiscal year ended April 1, 2016 (fiscal 2016). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements and accompanying notes. As a result, actual results may be different from these estimates. In the opinion of the Company's management, the accompanying unaudited Condensed Consolidated Financial Statements of CSC contain all adjustments necessary, including those of a normal recurring nature, to present fairly the Company's financial position as of December 30, 2016 and April 1, 2016 and its results of operations and cash flows for the three and nine months ended December 30, 2016 and January 1, 2016. The results of operations for such interim periods are not necessarily indicative of the results for the full year ending March 31, 2017. Certain prior year amounts have been reclassified to conform to the current year presentation.
Fiscal period	The Company reports its results based on a fiscal year convention that comprises four thirteen-week quarters. Every fifth year includes an additional week in the first quarter to prevent the fiscal year from moving from an approximate end of March date.
New Accounting Standards and Standards Issued But Not Yet Effective	New Accounting Standards During the first nine months of fiscal 2017, the Company adopted the following ASUs: ASU 2015-16, Business Combinations (Topic 805), "Simplifying the Accounting for Measurement Period Adjustments," requires an acquirer in a business combination to account for a measurement-period adjustment during the period in which the amount is determined, instead of retrospectively. CSC adopted this ASU effective April 2, 2016, and the impact on the Company's unaudited Condensed Consolidated Financial Statements was immaterial. ASU 2015-03, "Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs," as clarified by ASU 2015-15, "Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements—Amendments to SEC Paragraphs Pursuant to Staff Announcement at June 18, 2015, EITF Meeting," states that debt issuance costs are presented in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Presentation of fees under line-of-credit (LOC) arrangements had not been specified in ASU 2015-03; as a result, ASU 2015-15 was issued. ASU 2015-15 states that the SEC staff would not object to an entity deferring LOC commitment fees as an asset and subsequently amortizing ratably over the term of the underlying LOC arrangement, regardless of whether there are outstanding borrowings under that LOC arrangement. CSC adopted both ASUs effective April 2, 2016, and the impact upon the unaudited Condensed Consolidated Financial Statements was immaterial. ASU 2015-05, "Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement," issued guidance about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement does not contain a software license, the customer should account for the arrangement as a service contract. If the arrangement includes software licenses, it should be accounted for and considered as other licenses of intangible assets. CSC elected to adopt this ASU prospectively effective April 2, 2016. Adoption of this ASU did not have a material impact on the unaudited Condensed Consolidated Financial Statements. Standards Issued But Not Yet Effective The following ASUs were recently issued but have not yet been adopted by CSC: In January 2017, the Financial Accounting Standards Board (FASB) issued ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” which adds guidance to assisting companies evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or as businesses, and provides for a screen to determine when a transaction should be accounted for as the acquisition or disposal of assets and not of a business, potentially reducing the number of transactions that need to be further evaluated. ASU 2017-01 is effective for CSC in fiscal year 2019, applied on a prospective basis, and early application is allowed for certain transactions. CSC will evaluate any potential business combinations that may occur in the future. In December 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force,” which requires that amounts described as restricted cash or cash equivalents must be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for CSC in fiscal year 2019 and must be applied retrospectively to all periods presented. CSC is currently evaluating the impact, if any, that the adoption of ASU 2016-18 may have on its statements of cash flows in future reporting periods. In October 2016, the FASB issued ASU 2016-17, “Consolidation (Topic 810): Interests held through Related Parties that are under Common Control,” which alters how a decision maker considers indirect interests in a variable interest entity (VIE) held through an entity under common control and simplifies that analysis to require consideration of only an entity’s proportionate indirect interest in a VIE held through a common control party. ASU 2016-17 amends ASU 2015-02, “Consolidations (Topic 810): Amendments to the Consolidation Analysis,” adopted by CSC in the first three months of fiscal 2017, which did not have a material impact upon the unaudited Condensed Consolidated Financial Statements. ASU 2016-17 will be effective for CSC in fiscal year 2018 and will be required to be applied retrospectively to all relevant periods in fiscal 2017 when ASU 2015-02 was initially applied. CSC has determined the adoption of ASU 2016-17 will not have a material impact on its financial statements in future reporting periods. In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-entity Asset Transfers of Assets Other than Inventory,” which requires that an entity recognize the tax expense from intra-entity sales of assets, other than inventory, in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. ASU 2016-16 will be effective for CSC in fiscal year 2019 and early adoption is permitted as of the beginning of a fiscal year. The new standard must be adopted using a modified retrospective transition method which is a cumulative-effective adjustment to retained earnings as of the beginning of the first effective reporting period. CSC is currently evaluating the impact of ASU 2016-16 on its consolidated financial position and results of operations. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which addressed eight cash flow classification issues that have created diversity in practice, providing definitive guidance on classification of certain cash receipts and payments. ASU 2016-15 will be effective for CSC in fiscal year 2019 and early adoption is permitted. This ASU must be adopted retrospectively for all periods presented but may be applied prospectively if retrospective application would be impracticable. CSC is currently evaluating the impact that adoption of ASU 2016-15 may have on its statements of cash flows in future reporting periods. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments," which is intended to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the existing incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 will be effective for CSC in fiscal 2020. This ASU must be adopted using a prospective transition approach for debt securities for which an other-than-temporary impairment had been recognized before the effective date. CSC is currently evaluating the impact that the adoption of ASU 2016-13 may have on its financial statements in future reporting periods. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)." This amendment is intended to increase transparency and comparability among organizations by recognizing virtually all lease assets and lease liabilities on the balance sheet and disclosing key information about lease arrangements. ASU 2016-02 will be effective for CSC in fiscal 2020 and early adoption is permitted. This ASU must be adopted using a modified retrospective transition and provides for certain practical expedients. CSC is currently evaluating the effect the adoption of ASU 2016-02 will have on its existing accounting policies and the consolidated financial statements in future reporting periods, but expects there will be an increase in assets and liabilities on its balance sheets at adoption due to the recording of right-of-use assets and corresponding lease liabilities, which may be significant. Refer to Note 23 - Commitments and Contingencies of the Annual Report on Form 10-K for the fiscal year ended April 1, 2016, for information about the Company’s operating lease obligations. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities," which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 will be effective for CSC in fiscal 2019. This ASU should be applied prospectively to equity investments that exist as of the date of adoption for equity securities without readily determinable fair values. CSC is currently evaluating the impact that adoption of ASU 2016-01 may have on its financial statements in future reporting periods. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in ASC Topic 605, “Revenue Recognition” and some cost guidance included in ASC Subtopic 605-35, "Revenue Recognition - Construction-Type and Production-Type Contracts.” The core principle of ASU 2014-09 is that revenue is recognized when the transfer of goods or services to customers occurs in an amount that reflects the consideration to which CSC expects to be entitled in exchange for those goods or services. ASU 2014-09 requires the disclosure of sufficient information to enable readers of CSC’s financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. ASU 2014-09 also requires disclosure of information regarding significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU 2014-09 provides two methods of retrospective application. The first method would require CSC to apply ASU 2014-09 to each prior reporting period presented. The second method would require CSC to retrospectively apply ASU 2014-09 with the cumulative effect recognized at the date of initial application. ASU 2014-09 will be effective for CSC beginning in fiscal 2019 as a result of ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which was issued by the FASB in August 2015 and extended the original effective date by one year. CSC is currently evaluating the impact of adopting the available methodologies of ASU 2014-09 and 2015-14 upon its financial statements in future reporting periods. The Company has not yet selected a transition method. The Company is in the process of evaluating the new standard against its existing accounting policies, including the timing of revenue recognition, and its contracts with customers to determine the effect the guidance will have on its financial statements and what changes to systems and controls may be warranted. There have been four new ASUs issued amending certain aspects of ASU 2014-09, ASU 2016-08, "Principal versus Agent Considerations (Reporting Revenue Gross Versus Net)," was issued in March, 2016 to clarify certain aspects of the principal versus agent guidance in ASU 2014-09. In addition, ASU 2016-10, "Identifying Performance Obligations and Licensing," issued in April 2016, amends other sections of ASU 2014-09 including clarifying guidance related to identifying performance obligations and licensing implementation. ASU 2016-12, "Revenue from Contracts with Customers - Narrow Scope Improvements and Practical Expedients" provides amendments and practical expedients to the guidance in ASU 2014-09 in the areas of assessing collectability, presentation of sales taxes received from customers, noncash consideration, contract modification and clarification of using the full retrospective approach to adopt ASU 2014-09. Finally, ASU 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers,” was issued in December 2016, and provides elections regarding the disclosures required for remaining performance obligations in certain cases and also makes other technical corrections and improvements to the standard. With its evaluation of the impact of ASU 2014-09, CSC will also consider the impact on its financial statements related to the updated guidance provided by these four new ASUs. Other recently issued ASUs effective after January 1, 2017 are not expected to have a material effect on CSC's financial statements in future reporting periods.

New Accounting Standards

During the first nine months of fiscal 2017, the Company adopted the following ASUs:

ASU 2015-16, Business Combinations (Topic 805), "Simplifying the Accounting for Measurement Period Adjustments," requires an acquirer in a business combination to account for a measurement-period adjustment during the period in which the amount is determined, instead of retrospectively. CSC adopted this ASU effective April 2, 2016, and the impact on the Company's unaudited Condensed Consolidated Financial Statements was immaterial.

ASU 2015-03, "Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs," as clarified by ASU 2015-15, "Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements—Amendments to SEC Paragraphs Pursuant to Staff Announcement at June 18, 2015, EITF Meeting," states that debt issuance costs are presented in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Presentation of fees under line-of-credit (LOC) arrangements had not been specified in ASU 2015-03; as a result, ASU 2015-15 was issued. ASU 2015-15 states that the SEC staff would not object to an entity deferring LOC commitment fees as an asset and subsequently amortizing ratably over the term of the underlying LOC arrangement, regardless of whether there are outstanding borrowings under that LOC arrangement. CSC adopted both ASUs effective April 2, 2016, and the impact upon the unaudited Condensed Consolidated Financial Statements was immaterial.

ASU 2015-05, "Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement," issued guidance about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement does not contain a software license, the customer should account for the arrangement as a service contract. If the arrangement includes software licenses, it should be accounted for and considered as other licenses of intangible assets. CSC elected to adopt this ASU prospectively effective April 2, 2016. Adoption of this ASU did not have a material impact on the unaudited Condensed Consolidated Financial Statements.

Standards Issued But Not Yet Effective

The following ASUs were recently issued but have not yet been adopted by CSC:

In January 2017, the Financial Accounting Standards Board (FASB) issued ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” which adds guidance to assisting companies evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or as businesses, and provides for a screen to determine when a transaction should be accounted for as the acquisition or disposal of assets and not of a business, potentially reducing the number of transactions that need to be further evaluated. ASU 2017-01 is effective for CSC in fiscal year 2019, applied on a prospective basis, and early application is allowed for certain transactions. CSC will evaluate any potential business combinations that may occur in the future.

In December 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force,” which requires that amounts described as restricted cash or cash equivalents must be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for CSC in fiscal year 2019 and must be applied retrospectively to all periods presented. CSC is currently evaluating the impact, if any, that the adoption of ASU 2016-18 may have on its statements of cash flows in future reporting periods.

In October 2016, the FASB issued ASU 2016-17, “Consolidation (Topic 810): Interests held through Related Parties that are under Common Control,” which alters how a decision maker considers indirect interests in a variable interest entity (VIE) held through an entity under common control and simplifies that analysis to require consideration of only an entity’s proportionate indirect interest in a VIE held through a common control party. ASU 2016-17 amends ASU 2015-02, “Consolidations (Topic 810): Amendments to the Consolidation Analysis,” adopted by CSC in the first three months of fiscal 2017, which did not have a material impact upon the unaudited Condensed Consolidated Financial Statements. ASU 2016-17 will be effective for CSC in fiscal year 2018 and will be required to be applied retrospectively to all relevant periods in fiscal 2017 when ASU 2015-02 was initially applied. CSC has determined the adoption of ASU 2016-17 will not have a material impact on its financial statements in future reporting periods.

In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-entity Asset Transfers of Assets Other than Inventory,” which requires that an entity recognize the tax expense from intra-entity sales of assets, other than inventory, in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. ASU 2016-16 will be effective for CSC in fiscal year 2019 and early adoption is permitted as of the beginning of a fiscal year. The new standard must be adopted using a modified retrospective transition method which is a cumulative-effective adjustment to retained earnings as of the beginning of the first effective reporting period. CSC is currently evaluating the impact of ASU 2016-16 on its consolidated financial position and results of operations.

In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which addressed eight cash flow classification issues that have created diversity in practice, providing definitive guidance on classification of certain cash receipts and payments. ASU 2016-15 will be effective for CSC in fiscal year 2019 and early adoption is permitted. This ASU must be adopted retrospectively for all periods presented but may be applied prospectively if retrospective application would be impracticable. CSC is currently evaluating the impact that adoption of ASU 2016-15 may have on its statements of cash flows in future reporting periods.

In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments," which is intended to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the existing incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 will be effective for CSC in fiscal 2020. This ASU must be adopted using a prospective transition approach for debt securities for which an other-than-temporary impairment had been recognized before the effective date. CSC is currently evaluating the impact that the adoption of ASU 2016-13 may have on its financial statements in future reporting periods.

In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)." This amendment is intended to increase transparency and comparability among organizations by recognizing virtually all lease assets and lease liabilities on the balance sheet and disclosing key information about lease arrangements. ASU 2016-02 will be effective for CSC in fiscal 2020 and early adoption is permitted. This ASU must be adopted using a modified retrospective transition and provides for certain practical expedients. CSC is currently evaluating the effect the adoption of ASU 2016-02 will have on its existing accounting policies and the consolidated financial statements in future reporting periods, but expects there will be an increase in assets and liabilities on its balance sheets at adoption due to the recording of right-of-use assets and corresponding lease liabilities, which may be significant. Refer to Note 23 - Commitments and Contingencies of the Annual Report on Form 10-K for the fiscal year ended April 1, 2016, for information about the Company’s operating lease obligations.

In January 2016, the FASB issued ASU 2016-01, "Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities," which updates certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 will be effective for CSC in fiscal 2019. This ASU should be applied prospectively to equity investments that exist as of the date of adoption for equity securities without readily determinable fair values. CSC is currently evaluating the impact that adoption of ASU 2016-01 may have on its financial statements in future reporting periods.

In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in ASC Topic 605, “Revenue Recognition” and some cost guidance included in ASC Subtopic 605-35, "Revenue Recognition - Construction-Type and Production-Type Contracts.” The core principle of ASU 2014-09 is that revenue is recognized when the transfer of goods or services to customers occurs in an amount that reflects the consideration to which CSC expects to be entitled in exchange for those goods or services. ASU 2014-09 requires the disclosure of sufficient information to enable readers of CSC’s financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. ASU 2014-09 also requires disclosure of information regarding significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU 2014-09 provides two methods of retrospective application. The first method would require CSC to apply ASU 2014-09 to each prior reporting period presented. The second method would require CSC to retrospectively apply ASU 2014-09 with the cumulative effect recognized at the date of initial application. ASU 2014-09 will be effective for CSC beginning in fiscal 2019 as a result of ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which was issued by the FASB in August 2015 and extended the original effective date by one year. CSC is currently evaluating the impact of adopting the available methodologies of ASU 2014-09 and 2015-14 upon its financial statements in future reporting periods. The Company has not yet selected a transition method. The Company is in the process of evaluating the new standard against its existing accounting policies, including the timing of revenue recognition, and its contracts with customers to determine the effect the guidance will have on its financial statements and what changes to systems and controls may be warranted.

There have been four new ASUs issued amending certain aspects of ASU 2014-09, ASU 2016-08, "Principal versus Agent Considerations (Reporting Revenue Gross Versus Net)," was issued in March, 2016 to clarify certain aspects of the principal versus agent guidance in ASU 2014-09. In addition, ASU 2016-10, "Identifying Performance Obligations and Licensing," issued in April 2016, amends other sections of ASU 2014-09 including clarifying guidance related to identifying performance obligations and licensing implementation. ASU 2016-12, "Revenue from Contracts with Customers - Narrow Scope Improvements and Practical Expedients" provides amendments and practical expedients to the guidance in ASU 2014-09 in the areas of assessing collectability, presentation of sales taxes received from customers, noncash consideration, contract modification and clarification of using the full retrospective approach to adopt ASU 2014-09. Finally, ASU 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers,” was issued in December 2016, and provides elections regarding the disclosures required for remaining performance obligations in certain cases and also makes other technical corrections and improvements to the standard. With its evaluation of the impact of ASU 2014-09, CSC will also consider the impact on its financial statements related to the updated guidance provided by these four new ASUs.

Other recently issued ASUs effective after January 1, 2017 are not expected to have a material effect on CSC's financial statements in future reporting periods.