Pensions and Other Benefits - Pension and Other Benefits Recognized in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension and Other Postretirement Benefits Disclosure [Line Items]
Accumulated other comprehensive loss effects associated with accounting for pensions and other benefits in accordance with ASC Topic 715	$ 531	$ 678
Pension Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	252	12
Current liabilities	(1)	(9)
Noncurrent liabilities	(41)	(154)
Accumulated other comprehensive loss (b)	1,308	1,778
Net amount recognized	1,518	1,627
Other Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	535	326
Current liabilities	(3)	(4)
Noncurrent liabilities	(59)	(52)
Accumulated other comprehensive loss (b)	(767)	(659)
Net amount recognized	(294)	$ (389)
Retiree medical and life insurance | Other Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	$ 41