Pension And Postretirement Benefits (Net Periodic Benefit Cost (Credit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Net pension and postretirement cost (credit)	$ (4,789)	$ (7,652)	$ 711
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	617	957	1,029
Interest cost on projected benefit obligation	1,747	1,276	1,687
Expected return on assets	(3,107)	(3,513)	(3,557)
Amortization of prior service credit	(133)	(144)	(113)
Net periodic benefit cost (credit) before remeasurement	(876)	(1,424)	(954)
Actuarial (gain) loss	(115)	(3,461)	2,404
Net pension and postretirement cost (credit)	(991)	(4,885)	1,450
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	32	45	53
Interest cost on projected benefit obligation	277	210	416
Expected return on assets	(112)	(151)	(178)
Amortization of prior service credit	(2,558)	(2,537)	(2,329)
Net periodic benefit cost (credit) before remeasurement	(2,361)	(2,433)	(2,038)
Actuarial (gain) loss	(1,437)	(334)	1,299
Net pension and postretirement cost (credit)	$ (3,798)	$ (2,767)	$ (739)