Employee Benefit Plans (Net Periodic Costs (Components of Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plans | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 133	$ 122	$ 115
Interest cost	139	160	186
Expected return on plan assets	(273)	(302)	(288)
Amortization of prior service cost/(credit)	4	4	4
Amortization of actuarial (gain)/loss			4
Net periodic cost (benefit)	3	(16)	21
Current year prior service cost/(credit)	(4)		21
Amortization of prior service (cost)/credit	(4)	(4)	(4)
Current year actuarial loss/(gain)	(485)	(112)	(193)
Amortization of actuarial gain/(loss)			(4)
Total recognized in OCI	(493)	(116)	(180)
Total amounts recognized in net periodic cost and OCI	(490)	(132)	(159)
Pension Plans | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	3	3
Interest cost	6	8	10
Amortization of actuarial (gain)/loss	6	5	4
Net periodic cost (benefit)	16	16	17
Current year actuarial loss/(gain)	(4)	17	25
Amortization of actuarial gain/(loss)	(6)	(5)	(4)
Total recognized in OCI	(10)	12	21
Total amounts recognized in net periodic cost and OCI	6	28	38
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	4
Interest cost	8	11	13
Expected return on plan assets	(6)	(6)	(5)
Net periodic cost (benefit)	6	9	12
Current year actuarial loss/(gain)	(7)	3	9
Total recognized in OCI	(7)	3	9
Total amounts recognized in net periodic cost and OCI	$ (1)	$ 12	$ 21