Employee Benefits - Other Benefit Plans (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Active health care benefit expenses	$ 288	$ 296	$ 309
Participating employees' contribution to health care plan	$ 89	$ 101	120
Common stock included in the assets of the Defined Contribution Plan (in shares)	9	10
Expenses related to the 401(k) Plan	$ 87	$ 91	$ 96