Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Actuarial changes
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	$ 91	$ (51)	$ (40)
Prior service
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	58	(11)	(17)
Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	$ (2)	$ 0	$ (1)