FAIR VALUE MEASUREMENTS - Segregation of All Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2024	Mar. 31, 2024
Assets:
Short-term investments	$ 3.5	$ 22.0
Total financial assets	1,043.3	625.8
Liabilities:
Contingent earn-out consideration	0.5	12.4
Contingent earn-out consideration	2.8	0.7
Short-term debt, net, Convertible notes		24.6
Long-term debt, net, Convertible notes	26.0	25.9
Total financial liabilities	29.3	63.6
Money market funds
Assets:
Cash and cash equivalents	489.8	177.5
Restricted cash and cash equivalents	342.7	238.3
Restricted cash and cash equivalents, long term	86.0	95.9
Bank-time deposits
Assets:
Cash and cash equivalents	87.8	64.8
Short-term investments	3.5	22.0
Restricted cash and cash equivalents	0.5	0.5
Private equity
Assets:
Private equity	26.0	26.8
Equity securities
Assets:
Private equity	7.0
Quoted prices in active markets for identical assets (level 1)
Assets:
Total financial assets	1,017.3	599.0
Liabilities:
Contingent earn-out consideration	0.0	0.0
Contingent earn-out consideration	0.0	0.0
Short-term debt, net, Convertible notes		0.0
Long-term debt, net, Convertible notes	0.0	0.0
Total financial liabilities	0.0	0.0
Quoted prices in active markets for identical assets (level 1) | Money market funds
Assets:
Cash and cash equivalents	489.8	177.5
Restricted cash and cash equivalents	342.7	238.3
Restricted cash and cash equivalents, long term	86.0	95.9
Quoted prices in active markets for identical assets (level 1) | Bank-time deposits
Assets:
Cash and cash equivalents	87.8	64.8
Short-term investments	3.5	22.0
Restricted cash and cash equivalents	0.5	0.5
Quoted prices in active markets for identical assets (level 1) | Private equity
Assets:
Private equity	0.0	0.0
Quoted prices in active markets for identical assets (level 1) | Equity securities
Assets:
Private equity	7.0
Significant other observable inputs (level 2)
Assets:
Total financial assets	0.0	0.0
Liabilities:
Contingent earn-out consideration	0.0	0.0
Contingent earn-out consideration	0.0	0.0
Short-term debt, net, Convertible notes		24.6
Long-term debt, net, Convertible notes	26.0	25.9
Total financial liabilities	26.0	50.5
Significant other observable inputs (level 2) | Money market funds
Assets:
Cash and cash equivalents	0.0	0.0
Restricted cash and cash equivalents	0.0	0.0
Restricted cash and cash equivalents, long term	0.0	0.0
Significant other observable inputs (level 2) | Bank-time deposits
Assets:
Cash and cash equivalents	0.0	0.0
Short-term investments	0.0	0.0
Restricted cash and cash equivalents	0.0	0.0
Significant other observable inputs (level 2) | Private equity
Assets:
Private equity	0.0	0.0
Significant other observable inputs (level 2) | Equity securities
Assets:
Private equity	0.0
Significant unobservable inputs (level 3)
Assets:
Total financial assets	26.0	26.8
Liabilities:
Contingent earn-out consideration	0.5	12.4
Contingent earn-out consideration	2.8	0.7
Short-term debt, net, Convertible notes		0.0
Long-term debt, net, Convertible notes	0.0	0.0
Total financial liabilities	3.3	13.1
Significant unobservable inputs (level 3) | Money market funds
Assets:
Cash and cash equivalents	0.0	0.0
Restricted cash and cash equivalents	0.0	0.0
Restricted cash and cash equivalents, long term	0.0	0.0
Significant unobservable inputs (level 3) | Bank-time deposits
Assets:
Cash and cash equivalents	0.0	0.0
Short-term investments	0.0	0.0
Restricted cash and cash equivalents	0.0	0.0
Significant unobservable inputs (level 3) | Private equity
Assets:
Private equity	26.0	$ 26.8
Significant unobservable inputs (level 3) | Equity securities
Assets:
Private equity	$ 0.0