INVESTMENTS - Schedule of Cost and Fair Value of Investments in Debt Securities, by Contractual Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Amortized Cost
Due in 1 year or less	$ 53.0
Due after 1 year through 5 years	0.0
Instruments not due at a single maturity date	0.0
Amortized Cost	53.0
Fair Value
Due in 1 year or less	53.0
Due after 1 year through 5 years	0.0
Instruments not due at a single maturity date	0.0
Fair Value	53.0
Amortized Cost
Due in 1 year or less	706.0
Due after 1 year through 5 years	46.8
Instruments not due at a single maturity date	75.0
Amortized Cost	827.8	$ 1,026.4
Fair Value
Due in 1 year or less	704.9
Due after 1 year through 5 years	46.0
Instruments not due at a single maturity date	73.1
Fair Value	$ 824.0	$ 1,021.3