Benefit Obligations (Schedule of Net Periodic Benefit Costs Recognized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss on pension and postretirement plans	$ 41	$ 96	$ 87
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.50%	2.10%
Service cost	$ 13	$ 12	9
Interest cost	54	85	115
Expected return on plan assets	(205)	(199)	(185)
Actuarial (gain) loss on pension and postretirement plans	47	97	79
Curtailment (gain) loss	0	0	0
Special termination benefit	0	1	1
Total	(88)	(4)	19
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 3	$ 0	0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.50%	2.10%
Service cost	$ 1	$ 1	0
Interest cost	1	1	2
Expected return on plan assets	0	0	0
Actuarial (gain) loss on pension and postretirement plans	(6)	(1)	8
Curtailment (gain) loss	0	(1)	0
Special termination benefit	0	0	0
Total	(4)	0	10
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 0	$ 0	$ 0