SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding Commitments (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 16,448	$ 15,322
Liquidity facilities
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	519	1,108
Liquidity facilities | Non-agency-sponsored mortgage securitizations
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Asset-backed securities
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	519	1,108
Liquidity facilities | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Liquidity facilities | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	15,929	14,214
Loan / equity commitments | Non-agency-sponsored mortgage securitizations
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	130	0
Loan / equity commitments | Asset-backed securities
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	12,775	10,726
Loan / equity commitments | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	0	0
Loan / equity commitments | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	2,934	3,420
Loan / equity commitments | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	90	68
Loan / equity commitments | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 0	$ 0