Postretirement Plans - Schedule of Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Pension
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss/(gain)	$ 17,976	$ 18,175
Prior service credits	(922)	(1,143)
Total recognized in AOCI	17,054	17,032
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss/(gain)	(1,534)	(1,852)
Prior service credits	(8)	(19)
Total recognized in AOCI	$ (1,542)	$ (1,871)

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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