Earnings Per Share (Computation Of Basic Earnings And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 789	$ 837	$ 3,039
Weighted-average common stock outstanding - basic	284	289	293
Dilutive potential common shares related to stock award plans and from assumed exercise of stock options	2	3	2
Weighted Average Number of Shares Outstanding, Diluted	286	292	295
Basic	$ 2.78	$ 2.90	$ 10.37
Diluted	$ 2.76	$ 2.87	$ 10.30