v3.19.3.a.u2
Employee Benefit Plans (Components Of Net Periodic Pension Costs) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 31 $ 38 $ 38
Interest cost 80 75 77
Expected return on plan assets (137) (153) (143)
Amortization of actuarial loss 41 36 36
Settlement charge 2 0 12
Net periodic pension (benefit) cost 17 (4) 20
Qualified Plan [Member] | Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 28 35 34
Interest cost 75 70 72
Expected return on plan assets (137) (153) (143)
Amortization of actuarial loss 36 31 32
Settlement charge 0 0 0
Net periodic pension (benefit) cost 2 (17) (5)
Nonqualified Plan [Member] | Supplemental Employee Retirement Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 3 3 4
Interest cost 5 5 5
Expected return on plan assets 0 0 0
Amortization of actuarial loss 5 5 4
Settlement charge 2 0 12
Net periodic pension (benefit) cost $ 15 $ 13 $ 25