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Arbitrage Trading Account (Details) - USD ($) | Dec. 31, 2024 | Dec. 31, 2023
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Trading Securities and Derivative Instruments [Abstract] |  |
Arbitrage trading account | $ 1,123,000,000 | $ 938,000,000
Options Held | Short |  |
Derivative [Line Items] |  |
Other derivatives not designated as hedging instruments at fair value, net | 73,000,000 |
Derivative, notional amount | 582,000,000 |
Options Held | Long |  |
Derivative [Line Items] |  |
Other derivatives not designated as hedging instruments at fair value, net | 26,000,000 |
Derivative, notional amount | $ 582,000,000 |

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