Employee Benefits - Schedule of changes in Level 3 fair value for U.K. Pension Plans (Details) - Pension Plan - U.K. - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Actual return on plan assets:
Balance at the beginning of the period	$ 6,246	$ 6,652
Foreign exchange	(559)	(76)
Balance at the end of the period	3,537	6,246
Significant Unobservable Inputs (Level 3)
Actual return on plan assets:
Balance at the beginning of the period	2,305	2,625
Relating to assets still held at the end of the year	(674)	(286)
Purchases, sales and settlements-net	0	0
Foreign exchange	(228)	(34)
Balance at the end of the period	$ 1,403	$ 2,305