CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales		$ 1,322.6	$ 1,212.5
Cost of sales	[1]	507.4	570.5
Gross profit		815.2	642.0
Operating expenses:
Research and development	[1]	219.1	171.9
Selling, general and administrative	[1]	167.9	164.0
Amortization of acquired intangible assets		248.5	133.7
Special charges and other, net	[1]	8.1	40.1
Operating expenses		643.6	509.7
Operating income		171.6	132.3
Losses on equity method investments		0.0	(0.1)
Other income (expense):
Interest income		0.7	5.7
Interest expense		(132.6)	(90.4)
Loss on settlement of debt		(1.9)	0.0
Other income (loss), net		2.7	(9.8)
Income before income taxes		40.5	37.7
Income tax (benefit) provision		(10.2)	2.0
Net Income		$ 50.7	$ 35.7
Basic net income per common share
Basic net income per common share (in dollars per share)		$ 0.21	$ 0.15
Diluted net income per common share
Diluted net income per common share (in dollars per share)		0.20	0.14
Dividends declared per common share (in dollars per share)		$ 0.3655	$ 0.3635
Basic common shares outstanding (in shares)		237.8	235.2
Diluted common shares outstanding (in shares)		253.9	252.2

[1] (1) Includes share-based compensation expense as follows: Cost of sales$4.9 $3.6Research and development$19.5 $14.1Selling, general and administrative$16.3 $11.7Special charges and other, net$— $15.9