CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net sales	$ 5,438.4	$ 5,274.2	$ 5,349.5
Cost of sales	2,059.6	2,032.1	2,418.2
Gross profit	3,378.8	3,242.1	2,931.3
Research and development	836.4	877.8	826.3
Selling, general and administrative	610.3	676.6	682.9
Amortization of acquired intangible assets	932.3	993.9	674.1
Special charges and other, net	1.7	46.7	33.7
Operating expenses	2,380.7	2,595.0	2,217.0
Operating income	998.1	647.1	714.3
Losses on equity method investments	0.0	0.0	(0.2)
Other income (expense):
Interest income	1.7	2.8	8.1
Interest expense	(356.9)	(497.3)	(502.9)
Loss on settlement of debt	(299.6)	(5.4)	(12.6)
Other (loss) income, net	(3.8)	3.2	(2.2)
Income before income taxes	339.5	150.4	204.5
Income tax benefit	(9.9)	(420.2)	(151.4)
Net income	$ 349.4	$ 570.6	$ 355.9
Basic net income per common share (in dollars per share)	$ 1.35	$ 2.39	$ 1.51
Diluted net income per common share (in dollars per share)	1.29	2.23	1.42
Dividends declared per common share (in dollars per share)	$ 1.494	$ 1.465	$ 1.457
Basic common shares outstanding (in shares)	259.6	238.9	236.2
Diluted common shares outstanding (in shares)	270.6	256.2	249.9