Intangible Assets and Goodwill - Goodwill by Reporting Segment (Details) $ in Millions	12 Months Ended
	Mar. 31, 2024 USD ($) reporting_unit	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Goodwill By Reporting Segment [Line Items]
Goodwill	$ 6,675.4	$ 6,673.6
Number of reporting units | reporting_unit	2
Semiconductor Products Reporting Unit
Goodwill By Reporting Segment [Line Items]
Goodwill	$ 6,656.2	6,654.4	$ 6,654.4
Additions	1.8	0.0
Technology Licensing Reporting Unit
Goodwill By Reporting Segment [Line Items]
Goodwill	19.2	19.2	$ 19.2
Additions	$ 0.0	$ 0.0