Employment Benefit Plans AOCI (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Change in Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	$ 226	$ 509	$ 182
Amortization of net (gain) loss	(34)	3	2
Actuarial gain (loss)	93	(285)	326
Settlements	0	(1)	(1)
Ending balance	285	226	509
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net gain (loss)	$ 285	$ 226	$ 509

Defined Benefit Plan, Change in Accumulated Other Comprehensive Income Loss [Roll Forward]

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- Definition

Other Comprehensive Income Defined Benefit Plans Settlements

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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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- Definition

Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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