CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Adjustment	Common Stock and Additional Paid-in-Capital	Common Stock and Additional Paid-in-Capital Adjustment	Common Stock Held in Treasury	Accumulated Other Comprehensive Loss	Retained Earnings	Retained Earnings Adjustment
Balance, common stock shares issued (in shares) at Mar. 31, 2021			569,000,000.0
Beginning balance at Mar. 31, 2021	$ 5,337.1		$ 2,403.6		$ (433.8)	$ (26.2)	$ 3,393.5
Balance, common stock held in treasury (in shares) at Mar. 31, 2021					21,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	252.8						252.8
Other comprehensive income	0.0
Proceeds from sales of common stock through employee equity incentive plans (shares)			1,400,000
Proceeds from sales of common stock through employee equity incentive plans	12.2		$ 12.2
RSU and SAR withholdings (shares)			(400,000)
RSU and SAR withholdings	(25.3)		$ (25.3)
Treasury stock used for new issuances (shares)			(1,000,000.0)		(1,000,000.0)
Treasury stock used for new issuances	0.0		$ (16.3)		$ 16.3
Share-based compensation	56.2		$ 56.2
Cash dividend	(113.1)						(113.1)
Balance, common stock shares issued (in shares) at Jun. 30, 2021			569,000,000.0
Ending balance at Jun. 30, 2021	$ 5,519.9		$ 2,430.4		$ (417.5)	(26.2)	3,533.2
Balance, common stock held in treasury (in shares) at Jun. 30, 2021					20,900,000
Balance, common stock shares issued (in shares) at Mar. 31, 2022	577,805,396		577,800,000
Beginning balance at Mar. 31, 2022	$ 5,894.8		$ 2,536.5		$ (796.3)	(20.6)	4,175.2
Beginning balance (Accounting Standards Update 2020-06) at Mar. 31, 2022		$ (81.8)		$ (128.3)				$ 46.5
Balance, common stock held in treasury (in shares) at Mar. 31, 2022	23,304,872				23,300,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 507.2						507.2
Other comprehensive income	4.0					4.0
Proceeds from sales of common stock through employee equity incentive plans (shares)			1,200,000
Proceeds from sales of common stock through employee equity incentive plans	13.4		$ 13.4
RSU and SAR withholdings (shares)			(300,000)
RSU and SAR withholdings	(19.4)		$ (19.4)
Treasury stock used for new issuances (shares)			(900,000)		(900,000)
Treasury stock used for new issuances	$ 0.0		$ (16.5)		$ 16.5
Repurchase of common stock (in shares)	2,900,000				2,900,000
Repurchase of common stock	$ (195.2)				$ (195.2)
Settlement of convertible debt	(32.9)		(32.9)
Share-based compensation	40.8		$ 40.8
Cash dividend	$ (153.0)						(153.0)
Balance, common stock shares issued (in shares) at Jun. 30, 2022	577,805,396		577,800,000
Ending balance at Jun. 30, 2022	$ 5,977.9		$ 2,393.6		$ (975.0)	$ (16.6)	$ 4,575.9
Balance, common stock held in treasury (in shares) at Jun. 30, 2022	25,321,204				25,300,000