Earnings Per Share (Tables)

12 Months Ended

Mar. 31, 2018

Earnings Per Share Reconciliation [Abstract]

Computation Of Basic Earnings And Diluted Earnings Per Share

	Year Ended March 31,
(In millions, except per share amounts)	2018		2017		2016
Net income	$	1,043	$	967	$	1,156
Shares used to compute earnings per share:
Weighted-average common stock outstanding — basic	308		303		310
Dilutive potential common shares related to stock award plans and from assumed exercise of stock options	4		4		6
Dilutive potential common shares related to the Convertible Notes (a)	—		1		6
Dilutive potential common shares related to the Warrants (a)	—		6		8
Weighted-average common stock outstanding — diluted	312		314		330
Earnings per share:
Basic	$	3.39	$	3.19	$	3.73
Diluted	$	3.34	$	3.08	$	3.50