Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Actuarial changes
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	$ (24)	$ 36	$ 91
Prior service
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	(18)	(15)	58
Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
OCI, tax expense (benefit)	$ 0	$ 0	$ (2)