v3.25.4
FAIR VALUE MEASUREMENTS - Significant Valuation Input Sensitivity (Details)
$ in Thousands
Sep. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Sep. 30, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (239,694) $ (163,489)   $ (37,066)  
Loans held for sale, at fair value (389,032) (395,922) $ (468,142) (255,516) $ (245,890)
Residual interest securities          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities (38,308) (34,506)   (11,952)  
Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset (100,000) (88,497)   (55,860)  
Loans held for sale, at fair value $ (389,032) $ (369,983)   $ (255,516)  
Level 3 | Discount Rate          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0.129 0.129   0.129  
Loans Held For Sale, measurement input 0.055 0.076   0.105  
Level 3 | CPR          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0.135 0.142   0.142  
Loans Held For Sale, measurement input 0.131 0.137   0.163  
Level 3 | CDR          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0.007 0.007   0.011  
Loans Held For Sale, measurement input 0.014 0.017   0.016  
Level 3 | Servicing Rate          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0.003 0.002   0.001  
Loans Held For Sale, measurement input   0      
Level 3 | Residual interest securities          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (38,308) $ (34,506)   $ (11,952)  
Level 3 | Residual interest securities | Discount Rate | -2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (780) $ (1,599)      
Marketable Securities, measurement input 0.039 0.046      
Level 3 | Residual interest securities | Discount Rate | -1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (380) $ (699)      
Marketable Securities, measurement input 0.019 0.020      
Level 3 | Residual interest securities | Discount Rate | +1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (360) $ (1,163)      
Marketable Securities, measurement input (0.018) (0.034)      
Level 3 | Residual interest securities | Discount Rate | +2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (703) $ (2,124)      
Marketable Securities, measurement input (0.035) (0.062)      
Level 3 | Residual interest securities | CPR | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (1,001) $ 3,824      
Marketable Securities, measurement input 0.050 (0.111)      
Level 3 | Residual interest securities | CPR | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (513) $ 2,065      
Marketable Securities, measurement input 0.026 (0.060)      
Level 3 | Residual interest securities | CPR | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (464) $ 1,912      
Marketable Securities, measurement input (0.023) 0.055      
Level 3 | Residual interest securities | CPR | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (884) $ 4,160      
Marketable Securities, measurement input (0.044) 0.121      
Level 3 | Residual interest securities | CDR | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (274) $ (1,049)      
Marketable Securities, measurement input 0.014 0.030      
Level 3 | Residual interest securities | CDR | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (136) $ (424)      
Marketable Securities, measurement input 0.007 0.012      
Level 3 | Residual interest securities | CDR | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (135) $ (723)      
Marketable Securities, measurement input (0.007) (0.021)      
Level 3 | Residual interest securities | CDR | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Marketable Securities $ (269) $ (1,263)      
Marketable Securities, measurement input (0.014) (0.037)      
Level 3 | HELOC loans          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (98,120) $ (86,465)   (53,645)  
Loans held for sale, at fair value (323,184) (366,154)   $ (244,670)  
Level 3 | HELOC loans | Discount Rate | -2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (5,920) $ (5,510)      
Servicing Assets, measurement Input 0.062 0.063      
Loans held for sale, at fair value $ (16,052) $ (7,804)      
Loans Held For Sale, measurement input 0.034 0.023      
Level 3 | HELOC loans | Discount Rate | -1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (2,874) $ (2,668)      
Servicing Assets, measurement Input 0.030 0.030      
Loans held for sale, at fair value $ (10,890) $ (6,025)      
Loans Held For Sale, measurement input 0.023 0.018      
Level 3 | HELOC loans | Discount Rate | +1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (2,702) $ (2,514)      
Servicing Assets, measurement Input (0.028) (0.029)      
Loans held for sale, at fair value $ (14,240) $ (10,088)      
Loans Held For Sale, measurement input (0.030) (0.030)      
Level 3 | HELOC loans | Discount Rate | +2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (5,261) $ (4,880)      
Servicing Assets, measurement Input (0.055) (0.055)      
Loans held for sale, at fair value $ (29,376) $ (21,523)      
Loans Held For Sale, measurement input (0.062) (0.064)      
Level 3 | HELOC loans | CPR | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (6,044) $ (5,642)      
Servicing Assets, measurement Input 0.063 0.064      
Loans held for sale, at fair value $ (815) $ (616)      
Loans Held For Sale, measurement input 0.002 0.002      
Level 3 | HELOC loans | CPR | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (2,922) $ (2,721)      
Servicing Assets, measurement Input 0.031 0.031      
Loans held for sale, at fair value $ (488) $ (336)      
Loans Held For Sale, measurement input 0.001 0.001      
Level 3 | HELOC loans | CPR | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (2,740) $ (2,540)      
Servicing Assets, measurement Input (0.029) (0.029)      
Loans held for sale, at fair value $ (544) $ (351)      
Loans Held For Sale, measurement input (0.001) (0.001)      
Level 3 | HELOC loans | CPR | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (5,309) $ (4,924)      
Servicing Assets, measurement Input (0.056) (0.056)      
Loans held for sale, at fair value $ (1,245) $ (732)      
Loans Held For Sale, measurement input (0.003) (0.002)      
Level 3 | HELOC loans | CDR | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ 0        
Servicing Assets, measurement Input 0        
Loans held for sale, at fair value $ (1,599) $ (1,100)      
Loans Held For Sale, measurement input 0.003 0.003      
Level 3 | HELOC loans | CDR | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ 0        
Servicing Assets, measurement Input 0        
Loans held for sale, at fair value $ (807) $ (560)      
Loans Held For Sale, measurement input 0.002 0.002      
Level 3 | HELOC loans | CDR | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ 0        
Servicing Assets, measurement Input 0        
Loans held for sale, at fair value $ (819) $ (570)      
Loans Held For Sale, measurement input (0.002) (0.002)      
Level 3 | HELOC loans | CDR | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ 0        
Servicing Assets, measurement Input 0        
Loans held for sale, at fair value $ (1,628) $ (1,100)      
Loans Held For Sale, measurement input (0.004) (0.003)      
Level 3 | HELOC loans | Servicing Rate          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0.003 0.002   0.001  
Level 3 | HELOC loans | Servicing Rate | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (8,002) $ (6,020)      
Servicing Assets, measurement Input 0.084 0.068      
Level 3 | HELOC loans | Servicing Rate | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (4,001) $ (3,011)      
Servicing Assets, measurement Input 0.042 0.034      
Level 3 | HELOC loans | Servicing Rate | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (4,001) $ (3,006)      
Servicing Assets, measurement Input (0.042) (0.034)      
Level 3 | HELOC loans | Servicing Rate | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (8,002) $ (6,015)      
Servicing Assets, measurement Input (0.084) (0.068)      
Level 3 | Mortgage loans          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (1,880) $ (2,032)   $ (2,215)  
Level 3 | Mortgage loans | Discount Rate | -2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (238) $ (202)      
Servicing Assets, measurement Input 0.126 0.099      
Level 3 | Mortgage loans | Discount Rate | -1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (114) $ (97)      
Servicing Assets, measurement Input 0.061 0.048      
Level 3 | Mortgage loans | Discount Rate | +1%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (105) $ (89)      
Servicing Assets, measurement Input (0.056) (0.044)      
Level 3 | Mortgage loans | Discount Rate | +2%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (202) $ (171)      
Servicing Assets, measurement Input (0.108) (0.084)      
Level 3 | Mortgage loans | CPR | -20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (125) $ (114)      
Servicing Assets, measurement Input 0.067 0.056      
Level 3 | Mortgage loans | CPR | -10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (61) $ (56)      
Servicing Assets, measurement Input 0.033 0.027      
Level 3 | Mortgage loans | CPR | +10%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (59) $ (53)      
Servicing Assets, measurement Input (0.031) (0.026)      
Level 3 | Mortgage loans | CPR | +20%          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Asset $ (115) $ (105)      
Servicing Assets, measurement Input (0.061) (0.051)      
Level 3 | Mortgage loans | Servicing Rate          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Servicing Assets, measurement Input 0 0