Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 34	$ 31
Interest cost	57	55
Expected return on plan assets	(69)	(63)
Amortization of unrecognized (gain) loss	5	2
Amortization of prior service credit	0	0
Total	27	25
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	10	10
Expected return on plan assets	0	0
Amortization of unrecognized (gain) loss	(7)	(9)
Amortization of prior service credit	(23)	(28)
Total	$ (19)	$ (26)