Pension, Postretirement And Other Employee Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		$ 124	$ 204	$ 239
Interest cost		217	188	184
Expected return on plan assets		(251)	(306)	(283)
Amortization of unrecognized actuarial (gain) loss		8	120	170
Amortization of prior service credits		1	0	0
Special termination benefits - Voluntary Programs		0	0	0
Curtailment		0	0	(8)
Other		3	5	5
Net periodic benefit cost (credit)		102	211	307
Pension Benefits | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)	$ 108
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		4	9	10
Interest cost		42	30	25
Expected return on plan assets		(1)	(1)	(1)
Amortization of unrecognized actuarial (gain) loss		(38)	(14)	(28)
Amortization of prior service credits		(112)	(112)	(123)
Special termination benefits - Voluntary Programs		0	0	31
Curtailment		0	0	0
Other		0	0	0
Net periodic benefit cost (credit)		$ (105)	$ (88)	$ (86)
Other Postretirement Benefits | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost (credit)	$ (78)