v3.25.4
Statements of Consolidated Comprehensive Income (Loss) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Statement of Comprehensive Income [Abstract]      
Net Income $ 1,012.6 $ 844.7 $ 674.4
Other comprehensive income:      
Net unrealized gain (loss) on available-for-sale securities [1] 4.1 3.3 3.9
Net unrealized gain (loss) on cash flow hedges [2] (0.4) (0.4) (0.2)
Unrecognized pension and OPEB benefit (costs) [3] 20.5 0.3 (0.2)
Total other comprehensive income 24.2 3.2 3.5
Total Comprehensive Income $ 1,036.8 $ 847.9 $ 677.9
[1] Net unrealized gain on available-for-sale securities, net of $1.1 million tax expense, $0.9 million tax expense and $1.0 million tax expense in 2025, 2024 and 2023, respectively.
[2] Net unrealized loss on derivatives qualifying as cash flow hedges, net of $0.1 million tax benefit, $0.1 million tax benefit and $0.1 million tax benefit in 2025, 2024 and 2023, respectively.
[3] Unrecognized pension and OPEB benefit (costs), net of $4.4 million tax expense, $0.3 million tax expense and $0.1 million tax benefit in 2025, 2024 and 2023, respectively.