(Fair Value Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2018	Mar. 31, 2018
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total assets at fair value		$ 2,952	$ 3,292
Total liabilities at fair value		146	189
Quoted Prices In Active Markets For Identical Financial Instruments (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total assets at fair value		1,455	2,382
Total liabilities at fair value		12	11
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total assets at fair value		1,497	910
Total liabilities at fair value		10	56
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total assets at fair value		0	0
Total liabilities at fair value	[1]	124	122
Short-term investments | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities			210
Short-term investments | Significant Other Observable Inputs (Level 2) | Corporate bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities			624
Short-term investments | Significant Other Observable Inputs (Level 2) | U.S. agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		73	78
Short-term investments | Significant Other Observable Inputs (Level 2) | Debt Security, Government, Non-US [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		79	52
Short-term investments | Significant Other Observable Inputs (Level 2) | Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Asset-backed securities		121
Short-term investments | Significant Other Observable Inputs (Level 2) | Certificates of Deposit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		21
Short-Term Investments And Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		281
Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | Corporate bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		762
Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities		392	150
Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Bank Time Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Cash equivalents		24	286
Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Cash equivalents		1,138	1,876
Cash Equivalents | Significant Other Observable Inputs (Level 2) | Debt Security, Government, Non-US [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Available-for-sale of securities			2
Other Current Assets and Other Assets [Domain] | Significant Other Observable Inputs (Level 2) | Foreign currency derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Foreign currency derivatives, assets		49	4
Other assets | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred compensation plan assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Deferred compensation plan assets	[2]	12	10
Accrued and Other Current Liabilities and Other Liabilities | Significant Other Observable Inputs (Level 2) | Foreign currency derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Foreign currency derivatives, liabilities		10	56
Accrued and Other Current Liabilities and Other Liabilities | Fair Value, Inputs, Level 3 [Member] | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Accrued Liabilities, Fair Value Disclosure	[1]	124
Other liabilities | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred Compensation Plan Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value, Deferred compensation plan assets	[2]	12	11
Other liabilities | Fair Value, Inputs, Level 3 [Member] | Contingent consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Accrued Liabilities, Fair Value Disclosure	[1]	$ 124	$ 122

[1] The contingent consideration represents the estimated fair value of the additional variable cash consideration payable in connection with our acquisition of Respawn Entertainment, LLC (“Respawn”) that is contingent upon the achievement of certain performance milestones. We estimated fair value using a probability-weighted income approach combined with a real options methodology, and applied a discount rate that appropriately captures the risk associated with the obligation. At September 30, 2018, the discount rates used ranged from 3.3 percent to 3.7 percent. At March 31, 2018, the discount rates used ranged from 3.3 percent to 3.6 percent. See Note 6 in our Annual Report on Form 10-K for the fiscal year ended March 31, 2018, for additional information regarding the Respawn acquisition.

[2] The Deferred Compensation Plan assets consist of various mutual funds. See Note 14 in our Annual Report on Form 10-K for the fiscal year ended March 31, 2018, for additional information regarding our Deferred Compensation Plan.