v3.26.1
Accumulated Other Comprehensive Loss - Schedule of Reclassification Out of Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Interest expense - Borrowed funds $ 536 $ 724 $ 1,077 $ 1,478
Income tax (benefit) (14) 11 (25) 32
General and administrative 63 72 127 151
Net income (loss) 34 (70) 55 (170)
Reclassification from AOCI        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Net income (loss) 0 5 0 11
Reclassification from AOCI | Cash Flow Hedges        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Interest expense - Borrowed funds 0 7 0 16
Income tax (benefit) 0 (2) 0 (4)
Net income (loss) 0 5 0 12
Reclassification from AOCI | Pension and Post-retirement Plans        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Net income (loss) 0 0 0 (1)
Reclassification from AOCI | Amortization of actuarial losses        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Income tax (benefit) 0 1 0 1
General and administrative $ 0 $ (1) $ 0 $ (2)