Fair Value Measurements (Fair Value of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets at fair value	$ 740	$ 3,490
Total liabilities at fair value	36	59
Fair value, Available-for-sale of securities	330	1,106
Quoted Prices In Active Markets For Identical Financial Instruments (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets at fair value	437	2,712
Total liabilities at fair value	22	19
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets at fair value	303	778
Total liabilities at fair value	14	40
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets at fair value	0	0
Total liabilities at fair value	0	0
Short-Term Investments [Member] | Debt Security, Government, Non-US [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	17
Short-Term Investments [Member] | Certificates of Deposit [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	18
Short-Term Investments [Member] | Asset-backed Securities [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value	38
Short-Term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | US Agencies Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities		3
Short-Term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Debt Security, Government, Non-US [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	17	67
Short-Term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Certificates of Deposit [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	18	41
Short-Term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value	38	112
Short-Term Investments And Cash Equivalents [Member] | Corporate Bonds [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	116	380
Short-Term Investments And Cash Equivalents [Member] | U.S. Treasury Securities [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	104	437
Short-Term Investments And Cash Equivalents [Member] | US Agencies Securities [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities		3
Short-Term Investments And Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	51	142
Short-Term Investments And Cash Equivalents [Member] | Debt Security, Government, Non-US [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities		67
Short-Term Investments And Cash Equivalents [Member] | Certificates of Deposit [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities		41
Short-Term Investments And Cash Equivalents [Member] | Asset-backed Securities [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value		112
Short-Term Investments And Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	104	437
Short-Term Investments And Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	116	380
Short-Term Investments And Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Available-for-sale of securities	51	142
Cash Equivalents [Member] | Bank Time Deposits [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Cash equivalents	55	157
Cash Equivalents [Member] | Money Market Funds [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Cash equivalents	257	2,100
Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Bank Time Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Cash equivalents	55	157
Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Money Market Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Cash equivalents	257	2,100
Other Current Assets and Other Assets [Domain] | Foreign Currency Derivatives [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Foreign currency derivatives, assets	63	33
Other Current Assets and Other Assets [Domain] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Currency Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Foreign currency derivatives, assets	63	33
Other Assets [Member] | Deferred compensation plan assets | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Deferred compensation plan assets and liabilities	21	18
Other Assets [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred compensation plan assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Deferred compensation plan assets and liabilities	21	18
Accrued and Other Current Liabilities [Member] | Foreign Currency Derivatives [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Foreign currency derivatives, liabilities	14	40
Accrued and Other Current Liabilities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Currency Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Foreign currency derivatives, liabilities	14	40
Other Liabilities [Members] | Deferred Compensation Plan Liabilities [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Deferred compensation plan assets and liabilities	22	19
Other Liabilities [Members] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred Compensation Plan Liabilities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, Deferred compensation plan assets and liabilities	$ 22	$ 19