Special Charges (Income) and Other, Net - Special Charges (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Restructuring
Employee separation costs		$ 3.4	$ 3.3	$ 10.7	$ 60.5
Impairment charges		2.7	0.2	3.2	3.7
Contract exit costs		10.3	0.1	10.8	(2.9)
Other		1.4	0.1	2.6	0.7
Legal contingencies		0.0	(5.0)	2.2	(5.0)
Total	[1]	$ 17.8	$ (1.3)	$ 29.5	$ 57.0

[1] Three Months Ended December 31, Nine Months EndedDecember 31,(1) Includes share-based compensation expense as follows:2019 2018 2019 2018Cost of sales$5.7 $3.4 $15.8 $10.9Research and development$21.2 $19.4 $63.0 $53.2Selling, general and administrative$16.6 $16.6 $50.7 $46.1Special charges and other, net$— $0.2 $— $17.3