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Employee Benefits - Derivative Instruments (Details) - Combined Pension Plan - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
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Exchange-traded U.S. equity futures |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | $ 212 | $ 60
Exchange-traded Treasury and other interest rate futures |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 795 | 1,136
Exchange-traded Foreign currency futures |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 0 | 1
Interest rate swaps |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 149 | 214
Credit default swaps |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 124 | 72
Index swaps |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 701 | 94
Foreign exchange forwards |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | 47 | 57
Options |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Derivative, notional amount | $ 15 | $ 32

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