Benefit Plans - Summary of the Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net periodic pension cost:
Service cost	$ 93	$ 140	$ 186	$ 279
Interest cost	112	88	223	176
Estimated return on plan assets	(228)	(270)	(456)	(539)
Net amortization and other	19	9	39	17
Net periodic benefit cost (income)	$ (4)	$ (33)	$ (8)	$ (67)