Employee Benefit Plans (Schedule of PRB Amounts Recognized in Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain arising during the period	$ (1,291)	$ (3,246)	$ 202
Current year prior service cost	131	59	(2,095)
Amortization of prior service credit	(129)	(258)	$ (373)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain arising during the period	(209)	(88)
Amortization of actuarial gain	11	6
Amortization of prior service credit	2	3
Net settlement and curtailment	3	0
Total recognized in other comprehensive (income) loss	(193)	(79)
Net recognized in net periodic benefit (income) cost and other comprehensive loss	$ (196)	$ (78)