Employee Benefits - Schedule of Net Periodic Benefit (Income) Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Plans
Components of net periodic (benefit) expense
Service cost	$ 7	$ 11	$ 19	$ 34
Interest cost	67	53	202	155
Expected return on plan assets	(72)	(100)	(215)	(302)
Recognition of prior service cost (credit)	(2)	(3)	(5)	(8)
Recognition of actuarial loss	27	32	78	99
Net periodic expense (income)	27	(7)	79	(22)
Post-Retirement Benefit Plans
Components of net periodic (benefit) expense
Service cost	1	3	4	8
Interest cost	26	15	77	45
Recognition of prior service cost (credit)	(2)	1	(6)	5
Recognition of actuarial loss	(5)	0	(15)	0
Net periodic expense (income)	$ 20	$ 19	$ 60	$ 58