Benefit Plans (Projected Benefit Obligations, Plan Assets and Funded Status of Pension Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in plan assets:
Accrued pension costs	$ (133)	$ (200)
Accrued postretirement health care costs	(1,083)	(1,436)
Pension [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	8,544	9,465
Service cost	64	68	$ 74
Interest cost	206	184	251
Benefits paid	(462)	(465)
Actuarial (gains) losses	(2,060)	(523)
Plan amendments	0	8
Divestiture	0	(193)
Benefit obligation at end of year	6,292	8,544	9,465
Change in plan assets:
Fair value of plan assets at beginning of year	8,793	8,911
Actual return on plan assets	(1,748)	466
Employer contributions	20	26
Benefits paid	(462)	(465)
Divestiture	0	(145)
Fair value of plan assets at end of year	6,603	8,793	8,911
Funded status at December 31	311	249
Other assets	469	476
Other accrued liabilities	(25)	(27)
Accrued pension costs	(133)	(200)
Accrued postretirement health care costs	0	0
Defined benefit plan, amounts for asset (liability) recognized in statement of financial position	311	249
Postretirement Benefit Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	1,688	2,229
Service cost	23	20	16
Interest cost	41	38	59
Benefits paid	(87)	(104)
Actuarial (gains) losses	(392)	(150)
Plan amendments	2	(345)
Divestiture	0	0
Benefit obligation at end of year	1,275	1,688	2,229
Change in plan assets:
Fair value of plan assets at beginning of year	185	201
Actual return on plan assets	(35)	21
Employer contributions	0	0
Benefits paid	(28)	(37)
Divestiture	0	0
Fair value of plan assets at end of year	122	185	$ 201
Funded status at December 31	(1,153)	(1,503)
Other assets	0	0
Other accrued liabilities	(70)	(67)
Accrued pension costs	0	0
Accrued postretirement health care costs	(1,083)	(1,436)
Defined benefit plan, amounts for asset (liability) recognized in statement of financial position	$ (1,153)	$ (1,503)