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Fair Value Measurement - Level 3 Recurring Fair Value Rollforward (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Derivative, Fair Value, Net [Abstract] |  |  |
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent |  |
Derivative assets, gross amount | $ 2,675 | $ 3,098 |
Derivative liabilities, gross amount | 2,932 | 4,550 |
Recurring | Level 3 |  |  |
Derivative, Fair Value, Net [Abstract] |  |  |
Beginning balance | 5 |  |
Ending balance | 58 | 5 |
Net unrealized gains (losses) included in OCI related to assets and liabilities still held | (5) | 57 | $ 4
Derivative assets, gross amount | 886 | 79 | 84
Derivative liabilities, gross amount | 828 | 74 | 65
Total RMBS | Recurring | Level 3 |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Beginning balance | 236 | 258 | 328
Total Gains or (Losses) (Realized/Unrealized), Included in Net Income | 8 | 18 | 18
Total Gains or (Losses) (Realized/Unrealized), Included in OCI | (2) | (32) | 5
Purchases | 0 | 0 | 0
Sales | 0 | 0 | 0
Issuances | 0 | 0 | 0
Settlements | (20) | (60) | (91)
Transfers Into Level 3 | 49 | 123 | 106
Transfers Out of Level 3 | (125) | (71) | (108)
Ending balance | 146 | 236 | 258
Derivative, Fair Value, Net [Abstract] |  |  |
Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held | 7 | 10 | 15
CMBS | Recurring | Level 3 |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Beginning balance | 142 | 9 | 111
Total Gains or (Losses) (Realized/Unrealized), Included in Net Income | (1) | (1) | 0
Total Gains or (Losses) (Realized/Unrealized), Included in OCI | (4) | (3) | (2)
Purchases | 0 | 0 | 0
Sales | 0 | 0 | 0
Issuances | 0 | 0 | 0
Settlements | (5) | (15) | (7)
Transfers Into Level 3 | 0 | 190 | 0
Transfers Out of Level 3 | 0 | (38) | (93)
Ending balance | 132 | 142 | 9
Derivative, Fair Value, Net [Abstract] |  |  |
Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held | (1) | (1) | 0
Securities Available for Sale | Recurring | Level 3 |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Beginning balance | 378 | 267 | 439
Total Gains or (Losses) (Realized/Unrealized), Included in Net Income | 7 | 17 | 18
Total Gains or (Losses) (Realized/Unrealized), Included in OCI | (6) | (35) | 3
Purchases | 0 | 0 | 0
Sales | 0 | 0 | 0
Issuances | 0 | 0 | 0
Settlements | (25) | (75) | (98)
Transfers Into Level 3 | 49 | 313 | 106
Transfers Out of Level 3 | (125) | (109) | (201)
Ending balance | 278 | 378 | 267
Derivative, Fair Value, Net [Abstract] |  |  |
Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held | 6 | 9 | 15
Retained interests in securitizations | Recurring | Level 3 |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |
Beginning balance | 36 | 41 | 55
Total Gains or (Losses) (Realized/Unrealized), Included in Net Income | (1) | (5) | (14)
Total Gains or (Losses) (Realized/Unrealized), Included in OCI | 0 | 0 | 0
Purchases | 0 | 0 | 0
Sales | 0 | 0 | 0
Issuances | 0 | 0 | 0
Settlements | 0 | 0 | 0
Transfers Into Level 3 | 0 | 0 | 0
Transfers Out of Level 3 | 0 | 0 | 0
Ending balance | 35 | 36 | 41
Derivative, Fair Value, Net [Abstract] |  |  |
Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held | (1) | (5) | (14)
Net derivative assets (liabilities) | Recurring | Level 3 |  |  |
Derivative, Fair Value, Net [Abstract] |  |  |
Beginning balance | 5 | 19 | 31
Total Gains or (Losses) (Realized/Unrealized), Included in Net Income | (14) | (65) | (43)
Total Gains or (Losses) (Realized/Unrealized), Included in OCI | 0 | 0 | 0
Purchases | 0 | 0 | 0
Sales | 0 | 0 | 0
Issuances | 166 | 36 | 68
Settlements | 69 | 3 | (37)
Transfers Into Level 3 | (167) | (28) | 6
Transfers Out of Level 3 | (1) | 40 | (6)
Ending balance | 58 | 5 | 19
Net Unrealized Gains (Losses) Included in Net Income Related to Assets and Liabilities Still Held | $ 63 | $ (33) | $ (20)

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