Employee Benefit Plans (Net Periodic Costs (Components of Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plans | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 142	$ 133	$ 122
Interest cost	156	139	160
Expected return on plan assets	(298)	(273)	(302)
Amortization of prior service cost/(credit)	3	4	4
Net periodic cost (benefit)	3	3	(16)
Current year prior service cost/(credit)		(4)
Amortization of prior service (cost)/credit	(3)	(4)	(4)
Current year actuarial loss/(gain)	508	(485)	(112)
Total recognized in OCI	505	(493)	(116)
Total amounts recognized in net periodic cost and OCI	508	(490)	(132)
Pension Plans | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	4	3
Interest cost	7	6	8
Amortization of actuarial (gain)/loss	5	6	5
Net periodic cost (benefit)	15	16	16
Current year actuarial loss/(gain)	(44)	(4)	17
Amortization of actuarial gain/(loss)	(5)	(6)	(5)
Total recognized in OCI	(49)	(10)	12
Total amounts recognized in net periodic cost and OCI	(34)	6	28
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	4
Interest cost	9	8	11
Expected return on plan assets	(6)	(6)	(6)
Net periodic cost (benefit)	7	6	9
Current year actuarial loss/(gain)	(30)	(7)	3
Total recognized in OCI	(30)	(7)	3
Total amounts recognized in net periodic cost and OCI	$ (23)	$ (1)	$ 12