CONDENSED CONSOLIDATED STATEMENTS OF INCOME (PARENTHETICAL) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 40.7	$ 45.3
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	4.9	3.6
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	19.5	14.1
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	16.3	11.7
Special charges and other, net
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 0.0	$ 15.9