FAIR VALUE MEASUREMENT - Market Valuation Adjustments (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Dec. 31, 2025 |
|
| Credit and funding valuation adjustments contra-liability (contra-asset) | |||
| Counterparty CVA | $ (666) | $ (561) | |
| Asset FVA | (704) | (573) | |
| Citigroup (own credit) CVA | 396 | 331 | |
| Liability FVA | 204 | 185 | |
| Total CVA and FVA—derivative instruments | (770) | $ (618) | |
| Credit, Funding and Debt Valuation Adjustments Gain (Loss) [Abstract] | |||
| Counterparty CVA | (65) | $ (24) | |
| Asset FVA | (55) | 37 | |
| Own credit CVA | 97 | 46 | |
| Liability FVA | 48 | 5 | |
| Derivative Credit Risk and Funding Valuation Adjustment, Gain (Loss), Net | 25 | 64 | |
| DVA related to own FVO liabilities | 1,832 | 1,000 | |
| Total CVA, DVA and FVA | $ 1,857 | $ 1,064 | |