CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 1,649.8	$ 1,309.5	$ 3,219.2	$ 2,619.2
Cost of sales	581.5	501.6	1,143.3	1,013.0
Gross profit	1,068.3	807.9	2,075.9	1,606.2
Research and development	246.2	199.8	484.6	397.8
Selling, general and administrative	179.9	144.7	354.2	291.0
Amortization of acquired intangible assets	215.7	232.9	431.3	468.3
Special charges and other, net	10.2	4.3	20.7	4.6
Operating expenses	652.0	581.7	1,290.8	1,161.7
Operating income	416.3	226.2	785.1	444.5
Other income (expense):
Interest income	0.1	0.3	0.4	0.6
Interest expense	(64.8)	(93.3)	(137.1)	(192.4)
Loss on settlement of debt	(85.2)	(45.1)	(85.5)	(71.9)
Other (loss) income, net	(1.6)	0.7	(1.1)	(2.5)
Income before income taxes	264.8	88.8	561.8	178.3
Income tax provision (benefit)	22.8	15.2	67.0	(18.9)
Net income	$ 242.0	$ 73.6	$ 494.8	$ 197.2
Basic net income per common share (in dollars per share)	$ 0.44	$ 0.14	$ 0.90	$ 0.39
Diluted net income per common share (in dollars per share)	0.43	0.14	0.87	0.38
Dividends declared per common share (in dollars per share)	$ 0.2185	$ 0.1840	$ 0.4250	$ 0.3678
Basic common shares outstanding (in shares)	551.3	512.0	549.4	503.7
Diluted common shares outstanding (in shares)	565.9	535.3	565.5	525.5