CONSOLIDATED STATEMENT OF CASH FLOWS (PARENTHETICAL) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2019
Restricted cash	$ 42.1	$ 0.0	$ 38.4
2007 Junior Subordinated Convertible Notes
Shares issued to settle convertible debt (in shares)	3.7	12.0
Extinguishment of debt, amount	$ 143.8	$ 431.3
Long-term Debt | 2017 Junior Convertible Debt
Notes issued	$ 111.3
Long-term Debt | 2007 Junior Subordinated Convertible Notes
Shares issued to settle convertible debt (in shares)	3.2
Extinguishment of debt, amount	$ 111.3