Employee Benefits and Other Expenses, Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		153 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022
Employee Benefits and Other Expenses Textual [Abstract]
Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	5.00%
Net Periodic Benefit Cost, Discount Rate	2.47%
Qualified Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 5	$ 4
Interest cost	67	71
Expected return on plan assets	(139)	(152)
Amortization of net actuarial loss (gain)	33	37
Amortization of prior service credit	0	0
Settlement loss	47	0
Net periodic benefit cost	13	(40)
Nonqualified Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost	0	0
Interest cost	2	3
Expected return on plan assets	0	0
Amortization of net actuarial loss (gain)	3	4
Amortization of prior service credit	0	0
Settlement loss	1	2
Net periodic benefit cost	6	9
Other benefits plan assets [Member]
Components of net periodic benefit cost [Abstract]
Service cost	0	0
Interest cost	2	3
Expected return on plan assets	(5)	(5)
Amortization of net actuarial loss (gain)	(5)	(5)
Amortization of prior service credit	(3)	(2)
Settlement loss	0	0
Net periodic benefit cost	(11)	(9)
Cash balance plan [Member]
Components of net periodic benefit cost [Abstract]
Net periodic benefit cost			$ 0
Cash balance plan [Member] | Qualified Plan [Member]
Components of net periodic benefit cost [Abstract]
Settlement loss	$ 47	$ 0
Employee Benefits and Other Expenses Textual [Abstract]
Discount rate	3.65%		3.65%
Defined Benefit Plan, Plan Assets, (Increase) Decrease for Remeasurement due to Settlement	$ 10
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	$ 57