Financial Instruments (Fair Value Of Short-Term Investments) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022
Financial Instruments
Fair Value	$ 334	$ 330	[1]
Short-term investments
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	337	332
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(3)	(2)
Fair Value	334	330
Short-term investments | Corporate bonds
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	133	117
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	132	116
Short-term investments | U.S. Treasury securities
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	101	103
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	100	102
Short-term investments | U.S. agency securities
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	3	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	3	0
Short-term investments | Commercial paper
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	28	39
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	28	39
Short-term investments | Debt Security, Government, Non-US [Member]
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	18	17
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	18	17
Short-term investments | Asset-backed Securities [Member]
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	38	38
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	0
Fair Value	37	38
Short-term investments | Certificates of Deposit [Member]
Financial Instruments
Debt Securities, Available-for-sale, Amortized Cost	16	18
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 16	$ 18

[1] Derived from audited Consolidated Financial Statements.