v3.26.3
FAIR VALUE MEASUREMENTS - Schedule of financial assets and liabilities measured on recurring basis (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Securities and other investments owned:    
Total securities and other investments owned $ 305,488 $ 380,628
Loans receivable, at fair value 10,798 26,303
Total assets measured at fair value 316,286 406,931
Securities sold not yet purchased:    
Total securities sold not yet purchased 7,897 9,809
Embedded derivatives, included in accrued expenses and other liabilities 190  
Liability-classified warrants   6,400
Total liabilities measured at fair value 8,087 16,209
Equity securities    
Securities and other investments owned:    
Total securities and other investments owned 217,393 304,422
Securities sold not yet purchased:    
Total securities sold not yet purchased 6,829 9,342
Partnership interests and other investments    
Securities and other investments owned:    
Total securities and other investments owned 71,341 40,082
Corporate bonds    
Securities and other investments owned:    
Total securities and other investments owned 11,909 31,751
Securities sold not yet purchased:    
Total securities sold not yet purchased 241 467
Other fixed income securities    
Securities and other investments owned:    
Total securities and other investments owned 4,845 4,373
Securities sold not yet purchased:    
Total securities sold not yet purchased 827  
Quoted prices in active markets for identical assets (Level 1)    
Securities and other investments owned:    
Total securities and other investments owned 188,555 236,156
Loans receivable, at fair value 0 0
Total assets measured at fair value 188,555 236,156
Securities sold not yet purchased:    
Total securities sold not yet purchased 6,829 9,342
Embedded derivatives, included in accrued expenses and other liabilities 0  
Liability-classified warrants   0
Total liabilities measured at fair value 6,829 9,342
Quoted prices in active markets for identical assets (Level 1) | Equity securities    
Securities and other investments owned:    
Total securities and other investments owned 185,838 233,199
Securities sold not yet purchased:    
Total securities sold not yet purchased 6,829 9,342
Quoted prices in active markets for identical assets (Level 1) | Partnership interests and other investments    
Securities and other investments owned:    
Total securities and other investments owned 0 0
Quoted prices in active markets for identical assets (Level 1) | Corporate bonds    
Securities and other investments owned:    
Total securities and other investments owned 0 0
Securities sold not yet purchased:    
Total securities sold not yet purchased 0 0
Quoted prices in active markets for identical assets (Level 1) | Other fixed income securities    
Securities and other investments owned:    
Total securities and other investments owned 2,717 2,957
Securities sold not yet purchased:    
Total securities sold not yet purchased 0  
Other observable inputs (Level 2)    
Securities and other investments owned:    
Total securities and other investments owned 5,196 33,167
Loans receivable, at fair value 0 0
Total assets measured at fair value 5,196 33,167
Securities sold not yet purchased:    
Total securities sold not yet purchased 1,068 467
Embedded derivatives, included in accrued expenses and other liabilities 0  
Liability-classified warrants   0
Total liabilities measured at fair value 1,068 467
Other observable inputs (Level 2) | Equity securities    
Securities and other investments owned:    
Total securities and other investments owned 1,159 0
Securities sold not yet purchased:    
Total securities sold not yet purchased 0 0
Other observable inputs (Level 2) | Partnership interests and other investments    
Securities and other investments owned:    
Total securities and other investments owned 0 0
Other observable inputs (Level 2) | Corporate bonds    
Securities and other investments owned:    
Total securities and other investments owned 1,909 31,751
Securities sold not yet purchased:    
Total securities sold not yet purchased 241 467
Other observable inputs (Level 2) | Other fixed income securities    
Securities and other investments owned:    
Total securities and other investments owned 2,128 1,416
Securities sold not yet purchased:    
Total securities sold not yet purchased 827  
Significant unobservable inputs (Level 3)    
Securities and other investments owned:    
Total securities and other investments owned 111,737 111,305
Loans receivable, at fair value 10,798 26,303
Total assets measured at fair value 122,535 137,608
Securities sold not yet purchased:    
Total securities sold not yet purchased 0 0
Embedded derivatives, included in accrued expenses and other liabilities 190  
Liability-classified warrants   6,400
Total liabilities measured at fair value 190 6,400
Significant unobservable inputs (Level 3) | Equity securities    
Securities and other investments owned:    
Total securities and other investments owned 30,396 71,223
Securities sold not yet purchased:    
Total securities sold not yet purchased 0 0
Significant unobservable inputs (Level 3) | Partnership interests and other investments    
Securities and other investments owned:    
Total securities and other investments owned 71,341 40,082
Significant unobservable inputs (Level 3) | Corporate bonds    
Securities and other investments owned:    
Total securities and other investments owned 10,000 0
Securities sold not yet purchased:    
Total securities sold not yet purchased 0 0
Significant unobservable inputs (Level 3) | Other fixed income securities    
Securities and other investments owned:    
Total securities and other investments owned 0 $ 0
Securities sold not yet purchased:    
Total securities sold not yet purchased $ 0