INVESTMENT SECURITIES - Schedule of FHLB AND FRB Stock Purchases And Redemptions (Details) - USD ($) |
3 Months Ended | 9 Months Ended |
|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2026 |
|
| Investments, Debt and Equity Securities [Abstract] | ||
| Gain (loss) on redemption of FHLB stock | $ 0 | |
| FHLB stock purchased at par | $ 392,000,000 | 424,000,000 |
| FHLB stock redeemed at par | 182,000,000 | 264,000,000 |
| FRB stock purchased at par | 238,000,000 | 254,000,000 |
| FRB stock redeemed at par | $ 0 | $ 5,000,000 |