v3.26.1
Employee Benefits, Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 204 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Pension benefits qualified [Member]          
Components of net periodic benefit cost [Abstract]          
Service cost $ 8 $ 9 $ 17 $ 17  
Interest cost 88 97 176 195  
Expected return on plan assets (117) (123) (235) (246)  
Amortization of net actuarial loss (gain) 33 34 64 67  
Amortization of prior service credit 0 0 0 0  
Net periodic benefit cost 12 17 22 33  
Pension benefits nonqualified [Member]          
Components of net periodic benefit cost [Abstract]          
Service cost 0 0 0 0  
Interest cost 3 4 7 8  
Expected return on plan assets 0 0 0 0  
Amortization of net actuarial loss (gain) 0 0 1 1  
Amortization of prior service credit 0 0 0 0  
Net periodic benefit cost 3 4 8 9  
Other benefits [Member]          
Components of net periodic benefit cost [Abstract]          
Service cost 0 0 0 0  
Interest cost 3 3 6 6  
Expected return on plan assets (7) (7) (14) (14)  
Amortization of net actuarial loss (gain) (10) (6) (16) (12)  
Amortization of prior service credit (2) (2) (4) (5)  
Net periodic benefit cost $ (16) $ (12) $ (28) $ (25)  
Cash balance plan [Member]          
Employee Benefits and Other Expenses Textual [Abstract]          
New benefits accrued         $ 0