FAIR VALUE MEASUREMENTS - Segregation of All Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026
Assets:
Short-term investments	$ 461.7	$ 443.8
Total financial assets	1,552.4	1,682.9
Liabilities:
Short-term debt, net, Convertible notes	30.7	30.0
Total financial liabilities	30.8	30.0
Bank-time deposits
Assets:
Short-term investments	461.7	443.8
Private equity
Assets:
Private equity	26.5	23.6
Foreign currency forward contracts
Assets:
Foreign currency forward contracts		0.2
Liabilities:
Foreign currency forward contracts	0.1
Equity securities
Assets:
Private equity		9.3
Money market funds
Assets:
Cash and cash equivalents	774.6	909.0
Restricted cash and cash equivalents	12.5	11.9
Restricted cash and cash equivalents, long term	67.2	79.4
Bank-time deposits
Assets:
Cash and cash equivalents	208.4	204.5
Restricted cash and cash equivalents	1.5	1.2
Quoted prices in active markets for identical assets (level 1)
Assets:
Total financial assets	1,525.9	1,659.1
Liabilities:
Short-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) | Bank-time deposits
Assets:
Short-term investments	461.7	443.8
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) | Foreign currency forward contracts
Assets:
Foreign currency forward contracts		0.0
Liabilities:
Foreign currency forward contracts	0.0
Quoted prices in active markets for identical assets (level 1) | Equity securities
Assets:
Private equity		9.3
Quoted prices in active markets for identical assets (level 1) | Money market funds
Assets:
Cash and cash equivalents	774.6	909.0
Restricted cash and cash equivalents	12.5	11.9
Restricted cash and cash equivalents, long term	67.2	79.4
Quoted prices in active markets for identical assets (level 1) | Bank-time deposits
Assets:
Cash and cash equivalents	208.4	204.5
Restricted cash and cash equivalents	1.5	1.2
Significant other observable inputs (level 2)
Assets:
Total financial assets	0.0	0.2
Liabilities:
Short-term debt, net, Convertible notes	30.7	30.0
Total financial liabilities	30.8	30.0
Significant other observable inputs (level 2) | Bank-time deposits
Assets:
Short-term investments	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) | Foreign currency forward contracts
Assets:
Foreign currency forward contracts		0.2
Liabilities:
Foreign currency forward contracts	0.1
Significant other observable inputs (level 2) | Equity securities
Assets:
Private equity		0.0
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
Restricted cash and cash equivalents	0.0	0.0
Significant unobservable inputs (level 3)
Assets:
Total financial assets	26.5	23.6
Liabilities:
Short-term debt, net, Convertible notes	0.0	0.0
Total financial liabilities	0.0	0.0
Significant unobservable inputs (level 3) | Bank-time deposits
Assets:
Short-term investments	0.0	0.0
Significant unobservable inputs (level 3) | Private equity
Assets:
Private equity	26.5	23.6
Significant unobservable inputs (level 3) | Foreign currency forward contracts
Assets:
Foreign currency forward contracts		0.0
Liabilities:
Foreign currency forward contracts	0.0
Significant unobservable inputs (level 3) | Equity securities
Assets:
Private equity		0.0
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
Restricted cash and cash equivalents	$ 0.0	$ 0.0