v3.25.2
FAIR VALUE MEASUREMENTS - Securities Activity (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Purchases of Investments     $ 1,336.5 $ 1,190.1
I&M        
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Purchases of Investments     1,330.0 1,187.1
Spent Nuclear Fuel and Decommissioning Trusts        
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Proceeds from Investment Sales $ 717.9 $ 584.6 1,294.4 1,154.1
Purchases of Investments 728.8 598.6 1,330.0 1,187.1
Gross Realized Gains on Investment Sales 2.4 4.9 4.3 10.3
Gross Realized Losses on Investment Sales 1.8 4.2 2.5 5.4
Spent Nuclear Fuel and Decommissioning Trusts | I&M        
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]        
Proceeds from Investment Sales 717.9 584.6 1,294.4 1,154.1
Purchases of Investments 728.8 598.6 1,330.0 1,187.1
Gross Realized Gains on Investment Sales 2.4 4.9 4.3 10.3
Gross Realized Losses on Investment Sales $ 1.8 $ 4.2 $ 2.5 $ 5.4