Debt - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Debt issuance cost amortization			$ 9.2	$ 13.2
Debt discount amortization			34.9	57.5
Other interest expense	$ 1.8	$ 0.9	3.7	3.0
Total interest expense	62.1	86.5	199.2	278.9
Senior Secured Indebtedness
Debt Instrument [Line Items]
Debt issuance cost amortization	2.2	3.7	7.4	11.5
Debt discount amortization	1.7	1.6	5.3	4.7
Interest expense	45.3	59.2	144.9	171.3
Total interest expense	49.2	64.5	157.6	187.5
Convertible Debt
Debt Instrument [Line Items]
Debt issuance cost amortization	0.6	0.5	1.8	1.7
Debt discount amortization	9.0	12.8	29.6	52.8
Interest expense	1.5	7.8	6.5	33.9
Total interest expense	$ 11.1	$ 21.1	$ 37.9	$ 88.4