Earnings Per Share (Computation Of Basic Earnings And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share Reconciliation [Abstract]
Net income (loss)	$ 66	$ 211	$ 564	$ 761
Weighted Average Number of Shares Outstanding, Basic	283	290	284	289
Dilutive potential common shares related to stock award plans and from assumed exercise of stock options	2	2	3	3
Weighted Average Number of Shares Outstanding, Diluted	285	292	287	292
Earnings Per Share, Basic	$ 0.23	$ 0.73	$ 1.99	$ 2.63
Earnings Per Share, Diluted	$ 0.23	$ 0.72	$ 1.97	$ 2.61