v3.26.1
Employee Benefits, Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 201 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Pension benefits qualified [Member]      
Components of net periodic benefit cost [Abstract]      
Service cost $ 9 $ 8  
Interest cost 88 98  
Expected return on plan assets (118) (123)  
Amortization of net actuarial loss (gain) 31 33  
Amortization of prior service credit 0 0  
Net periodic benefit cost 10 16  
Pension benefits nonqualified [Member]      
Components of net periodic benefit cost [Abstract]      
Service cost 0 0  
Interest cost 4 4  
Expected return on plan assets 0 0  
Amortization of net actuarial loss (gain) 1 1  
Amortization of prior service credit 0 0  
Net periodic benefit cost 5 5  
Other benefits [Member]      
Components of net periodic benefit cost [Abstract]      
Service cost 0 0  
Interest cost 3 3  
Expected return on plan assets (7) (7)  
Amortization of net actuarial loss (gain) (6) (6)  
Amortization of prior service credit (2) (3)  
Net periodic benefit cost $ (12) $ (13)  
Cash balance plan [Member]      
Employee Benefits and Other Expenses Textual [Abstract]      
New benefits accrued     $ 0