v3.25.2
FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Assets:          
Unrealized gains on equity securities $ 110.7 $ 40.7 $ 118.3 $ 26.0  
Fair Value, Measurements, Recurring | Level 1          
Assets:          
Investments in equity securities 218.2   218.2   $ 98.6
Fair Value, Measurements, Recurring | Level 2          
Assets:          
Investments in equity securities 4.0   4.0   5.3
Fair Value, Measurements, Recurring | Level 3          
Assets:          
Investments in equity securities $ 0.0   $ 0.0   $ 0.0