Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension benefits paid
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 12	$ 25
Interest cost	47	97	235
Expected return on plan assets	(90)	(136)	(286)
Recognized net actuarial loss	56	78	139
Amortization of prior service cost (benefit)	1	0	2
Settlement	69	76	9
Curtailment benefit	6	0	0
Net periodic benefit cost	93	127	124
Discontinued operations	0	20	95
Net amount recognized in Statement of Consolidated Operations	93	107	29
Pension benefits paid | United States
Defined Benefit Plan Disclosure [Line Items]
Curtailment benefit			17
Net periodic benefit cost	61	58	127
Other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	7
Interest cost	5	10	28
Expected return on plan assets	0	0	0
Recognized net actuarial loss	0	3	4
Amortization of prior service cost (benefit)	(9)	(6)	(6)
Settlement	0	0	0
Curtailment benefit	0	(2)	(58)
Net periodic benefit cost	(2)	8	(25)
Discontinued operations	0	6	(15)
Net amount recognized in Statement of Consolidated Operations	(2)	2	(10)
Decrease in net periodic benefit cost for the recognition of the federal subsidy awarded under Medicare Part D (less than $1)	$ 1	$ 1	$ 11