Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent	$ 5,331	$ 3	$ 0	$ 5,358	$ (30)
Beginning balance (in shares) at Mar. 31, 2019		298,107
Beginning balance at Mar. 31, 2019	5,331	$ 3	0	5,358	(30)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss) before reclassifications	44
Amounts reclassified from accumulated other comprehensive income (loss)	(64)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	3,019			3,039	(20)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	347		347
Stock Issued During Period, Shares, New Issues		2,623
Stock Issued During Period, Value, New Issues	(29)		(29)
Stock Repurchased and Retired During Period, Shares		(12,317)
Stock Repurchased and Retired During Period, Value	(1,207)		(318)	(889)
Ending balance (in shares) at Mar. 31, 2020		288,413
Ending balance at Mar. 31, 2020	7,461	$ 3	0	7,508	(50)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent	7,461	$ 3	0	7,508	(50)
Other comprehensive income (loss) before reclassifications	(25)
Amounts reclassified from accumulated other comprehensive income (loss)	25
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	837			837	0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	435		435
Stock Issued During Period, Shares, New Issues		3,685
Stock Issued During Period, Value, New Issues	(66)		(66)
Stock Repurchased and Retired During Period, Shares		(5,633)
Stock Repurchased and Retired During Period, Value	$ (729)		(369)	(360)
Common Stock, Dividends, Per Share, Cash Paid	$ 0.34
Dividends, Common Stock, Cash	$ 98			98
Ending balance (in shares) at Mar. 31, 2021	286,000	286,465
Ending balance at Mar. 31, 2021	$ 7,840	$ 3	0	7,887	(50)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent	7,840	$ 3	0	7,887	(50)
Other comprehensive income (loss) before reclassifications	63
Amounts reclassified from accumulated other comprehensive income (loss)	2
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	854			789	65
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	528		528
Stock Issued During Period, Value, Acquisitions	23				23
Stock Issued During Period, Shares, New Issues		3,108
Stock Issued During Period, Value, New Issues	(127)		(127)
Stock Repurchased and Retired During Period, Shares		(9,522)
Stock Repurchased and Retired During Period, Value	$ (1,300)		(424)	(876)
Common Stock, Dividends, Per Share, Cash Paid	$ 0.68
Dividends, Common Stock, Cash	$ 193			193
Ending balance (in shares) at Mar. 31, 2022	280,000	280,051
Ending balance at Mar. 31, 2022	$ 7,625	$ 3	0	7,607	15
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent	$ 7,625	$ 3	$ 0	$ 7,607	$ 15