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Fair Value Measurements - Change in Fair Values of Level 3 Financial Instruments (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022
Other securities |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | $ 0 | $ 0
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | 0 | 0
Purchases | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Transfers Other | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 0 | 0
Unrealized Gains (Losses) Included in Earnings | 0 | 0
Other investments |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 2 | 9
Gains (Losses) included in comprehensive income | 0 |
Gains (Losses) Included in Earnings | 0 | (3)
Purchases | 0 |
Sales | 0 | (4)
Settlements | 0 |
Transfers Other | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 2 | 2
Unrealized Gains (Losses) Included in Earnings | 0 |
Other investments | Principal investments: Direct |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 1 | 1
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | (1) | 0
Purchases | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Transfers Other | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 0 | 1
Unrealized Gains (Losses) Included in Earnings | 0 | 0
Interest rate |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 2 | 33
Gains (Losses) included in comprehensive income | 0 |
Gains (Losses) Included in Earnings | (23) | (72)
Purchases | 19 | 2
Sales | 1 | (2)
Settlements | 0 |
Transfers Other | 0 | 0
Transfers into Level 3 | (6) | 33
Transfers out of Level 3 | 5 | 8
End of Period Balance | (2) | 2
Unrealized Gains (Losses) Included in Earnings | 0 |
Credit |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | (2) | (6)
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | 0 | 4
Purchases | 0 | 0
Sales | 2 | 0
Settlements | 0 | 0
Transfers Other | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 |
End of Period Balance | 0 | (2)
Unrealized Gains (Losses) Included in Earnings | 0 | 0
Other |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 0 | 5
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | 0 | 0
Purchases | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Transfers Other | 2 | (5)
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 2 | 0
Unrealized Gains (Losses) Included in Earnings | 0 | 0
Loans held for sale (residential) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 0 | 0
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | 0 | 0
Purchases | 0 | 0
Sales | 0 | 0
Settlements | 0 | 0
Transfers Other | 0 | 0
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 0 | 0
Unrealized Gains (Losses) Included in Earnings | 0 | (3)
Loans held for investment (residential) |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |
Beginning of Period Balance | 9 | 11
Gains (Losses) included in comprehensive income | 0 | 0
Gains (Losses) Included in Earnings | 0 | (3)
Purchases | 0 | 0
Sales | 0 | (1)
Settlements | 0 | 0
Transfers Other | 0 | 2
Transfers into Level 3 | 0 | 0
Transfers out of Level 3 | 0 | 0
End of Period Balance | 9 | 9
Unrealized Gains (Losses) Included in Earnings | $ 0 | $ 0

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- Definition Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
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