Employee Benefit Plans - Components of Net Periodic Benefit Cost (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1	$ 3	$ 3
Interest cost	(45)	(28)	(135)	(84)
Expected return on plan assets	(58)	(50)	(176)	(151)
Amortization of prior service credit	0	0	0	0
Amortization of actuarial loss	(7)	(15)	(21)	(46)
Net periodic cost (benefit)	(5)	(6)	(17)	(18)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	(1)	(1)	(5)	(3)
Expected return on plan assets	0	(1)	(1)	(2)
Amortization of prior service credit	(2)	(2)	(5)	(5)
Amortization of actuarial loss	(2)	(2)	(4)	(5)
Net periodic cost (benefit)	$ 1	$ 0	$ 3	$ 1