v3.25.4
Fair Value of Financial Instruments - Schedule of Quantitative Information Regarding Significant and Unobservable Inputs Used in the Valuation of Level 3 Assets and Liabilities Measured at Fair Value (Details)
Dec. 31, 2025
USD ($)
month
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity investments $ 24,711,000 $ 113,492,000  
Mortgage servicing rights 20,893,000 21,003,000 $ 0
Greater than 90 days past due      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Fair value 0 0  
Level 3      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value 4,438,882,000    
Equity investments 24,711,000 113,492,000  
Mortgage servicing rights 20,893,000 21,003,000  
Level 3 | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity investments 24,711,000    
Level 3 | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Mortgage servicing rights 20,893,000    
Level 3 | IRLCs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Derivative asset, estimated fair value $ 691,000    
Level 3 | Default rate | Discounted cash flow | Weighted Average | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.024    
Level 3 | Default rate | Discounted cash flow | Minimum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0    
Level 3 | Default rate | Discounted cash flow | Maximum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.418    
Level 3 | Loss severity | Discounted cash flow | Weighted Average | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input 0    
Level 3 | Yield | Discounted cash flow | Weighted Average | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.122    
Level 3 | Yield | Discounted cash flow | Minimum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.120    
Level 3 | Yield | Discounted cash flow | Maximum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.140    
Level 3 | Discount rate | Discounted cash flow | Weighted Average | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input 0.159    
Level 3 | Discount rate | Discounted cash flow | Minimum | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input 0.150    
Level 3 | Discount rate | Discounted cash flow | Maximum | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input 0.175    
Level 3 | Months to assumed redemption | Discounted cash flow | Weighted Average | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input | month 14    
Level 3 | Months to assumed redemption | Discounted cash flow | Minimum | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input | month 2    
Level 3 | Months to assumed redemption | Discounted cash flow | Maximum | Equity investments      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Equity method investment, measurement input | month 26    
Level 3 | Lifetime voluntary prepayment rate | Discounted cash flow | Weighted Average | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.101    
Level 3 | Lifetime voluntary prepayment rate | Discounted cash flow | Minimum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.002    
Level 3 | Lifetime voluntary prepayment rate | Discounted cash flow | Maximum | MSRs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Servicing asset, measurement input 0.289    
Level 3 | Pull-through rate | Probability-weighted expected cash flow | Weighted Average | IRLCs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Derivative asset, measurement Input 0.774    
Level 3 | Pull-through rate | Probability-weighted expected cash flow | Minimum | IRLCs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Derivative asset, measurement Input 0.770    
Level 3 | Pull-through rate | Probability-weighted expected cash flow | Maximum | IRLCs      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Derivative asset, measurement Input 0.789    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Discounted cash flow      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value $ 2,952,490,000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Liquidation model      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value 109,139,000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Transaction price      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value $ 211,576,000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Lifetime CPR | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.103    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Lifetime CPR | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Lifetime CPR | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.455    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Default rate | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.007    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Default rate | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Default rate | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.264    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Loss severity | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.128    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Loss severity | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Loss severity | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 1.000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.066    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.052    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.411    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Liquidation model | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.087    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Liquidation model | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.075    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Yield | Liquidation model | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 1.000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Annual home price appreciation/(depreciation) | Liquidation model | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.001    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Annual home price appreciation/(depreciation) | Liquidation model | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Annual home price appreciation/(depreciation) | Liquidation model | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 0.087    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Liquidation timeline (months) | Liquidation model | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input | month 16    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Liquidation timeline (months) | Liquidation model | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input | month 9    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Liquidation timeline (months) | Liquidation model | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input | month 54    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Property value | Liquidation model | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 1,815,175    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Property value | Liquidation model | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 15,000    
Level 3 | Residential loans, residential loans held in securitization trusts and residential loans held for sale | Property value | Liquidation model | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, measurement input 13,900,000    
Level 3 | Multi-family loans, at fair value      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value $ 55,476,000    
Level 3 | Multi-family loans, at fair value | Loss severity | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input 0    
Level 3 | Multi-family loans, at fair value | Discount rate | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input 0.123    
Level 3 | Multi-family loans, at fair value | Discount rate | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input 0.115    
Level 3 | Multi-family loans, at fair value | Discount rate | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input 0.135    
Level 3 | Multi-family loans, at fair value | Months to assumed redemption | Discounted cash flow | Weighted Average      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input | month 24    
Level 3 | Multi-family loans, at fair value | Months to assumed redemption | Discounted cash flow | Minimum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input | month 3    
Level 3 | Multi-family loans, at fair value | Months to assumed redemption | Discounted cash flow | Maximum      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Financial instruments owned, measurement input | month 42    
Level 3 | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Loans receivable, at fair value $ 1,165,677,000    
Variable interest entity, primary beneficiary, maximum loss exposure, amount 151,500,000 $ 148,500,000  
Level 3 | Consolidated SLST | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Collateralized debt obligations $ 1,006,919,000    
Level 3 | Consolidated SLST | Loss severity | Discounted cash flow | Weighted Average | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.153    
Level 3 | Consolidated SLST | Loss severity | Discounted cash flow | Minimum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0    
Level 3 | Consolidated SLST | Loss severity | Discounted cash flow | Maximum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.271    
Level 3 | Consolidated SLST | Yield | Discounted cash flow | Weighted Average | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.051    
Level 3 | Consolidated SLST | Yield | Discounted cash flow | Minimum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.032    
Level 3 | Consolidated SLST | Yield | Discounted cash flow | Maximum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.120    
Level 3 | Consolidated SLST | Collateral prepayment rate | Discounted cash flow | Weighted Average | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.061    
Level 3 | Consolidated SLST | Collateral prepayment rate | Discounted cash flow | Minimum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.025    
Level 3 | Consolidated SLST | Collateral prepayment rate | Discounted cash flow | Maximum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.072    
Level 3 | Consolidated SLST | Collateral default rate | Discounted cash flow | Weighted Average | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.011    
Level 3 | Consolidated SLST | Collateral default rate | Discounted cash flow | Minimum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0    
Level 3 | Consolidated SLST | Collateral default rate | Discounted cash flow | Maximum | Consolidated SLST | VIE, Primary Beneficiary      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Debt, measurement input 0.185