v3.26.1
Valuation (Schedule of Significant Unobservable Inputs, Qualitative Information) (Details) - Level 3
3 Months Ended
Mar. 31, 2026
USD ($)
$ / shares
Non-Agency RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 310,784,000
CMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 9,786,000
CLOs  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 37,367,000
Asset-backed securities, backed by consumer loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 168,559,000
Investment in unconsolidated entities  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 349,722,000
Agency Interest Only RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 12,347,000
Valuation, Market Approach | Non-Agency RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 140,765,000
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 0.45
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 179.88
Valuation, Market Approach | Non-Agency RMBS | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 31.97
Valuation, Market Approach | CMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 7,754,000
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 5.64
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 77.66
Valuation, Market Approach | CMBS | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 41.18
Valuation, Market Approach | CLOs  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 15,630,000
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 10.61
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 97.24
Valuation, Market Approach | CLOs | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 56.86
Valuation, Market Approach | Asset-backed securities, backed by consumer loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 95,131,000
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 2.20
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 100.12
Valuation, Market Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 69.10
Valuation, Market Approach | Other secured borrowings, at fair value  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ (3,125,332,000)
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.50
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 100.00
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 93.00
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.045
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.591
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.056
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.019
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.776
Valuation, Market Approach | Other secured borrowings, at fair value | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.496
Valuation, Market Approach | Unsecured Borrowings  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ (638,644,000)
Valuation, Market Approach | Unsecured Borrowings | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 81.50
Valuation, Market Approach | Unsecured Borrowings | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 99.10
Valuation, Market Approach | Unsecured Borrowings | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 96.40
Valuation, Market Approach | Agency Interest Only RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 6,296,000
Valuation, Market Approach | Agency Interest Only RMBS | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 1.19
Valuation, Market Approach | Agency Interest Only RMBS | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 18.99
Valuation, Market Approach | Agency Interest Only RMBS | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input | $ / shares 8.13
Valuation, Income Approach | Non-Agency RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 170,019,000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.011
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.868
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.167
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 1.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.825
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.575
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Default Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.044
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.495
Valuation, Income Approach | Non-Agency RMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.035
Valuation, Income Approach | CMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 2,032,000
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.104
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.263
Valuation, Income Approach | CMBS | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.179
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.930
Valuation, Income Approach | CMBS | Measurement Input, Default Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.120
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.070
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 1.000
Valuation, Income Approach | CMBS | Measurement Input, Projected Collateral Recoveries | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.875
Valuation, Income Approach | CLOs  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 21,737,000
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.037
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.654
Valuation, Income Approach | CLOs | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.170
Valuation, Income Approach | Agency RMBS | Measurement Input, LIBOR OAS | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.0016
Valuation, Income Approach | Agency RMBS | Measurement Input, LIBOR OAS | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.3258
Valuation, Income Approach | Agency RMBS | Measurement Input, LIBOR OAS | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.0548
Valuation, Income Approach | Asset-backed securities, backed by consumer loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 73,428,000
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.027
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.373
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.117
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.578
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.168
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.000
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.344
Valuation, Income Approach | Asset-backed securities, backed by consumer loans | Measurement Input, Default Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.193
Valuation, Income Approach | Corporate debt and equity  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 31,521,000
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.001
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.592
Valuation, Income Approach | Corporate debt and equity | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.180
Valuation, Income Approach | Consumer loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 135,000
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.120
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.122
Valuation, Income Approach | Consumer loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.120
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.302
Valuation, Income Approach | Consumer loans | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.096
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.006
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.823
Valuation, Income Approach | Consumer loans | Measurement Input, Default Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.217
Valuation, Income Approach | Corporate loan [Member]  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 31,479,000
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.260
Valuation, Income Approach | Corporate loan [Member] | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.139
Valuation, Income Approach | Credit default swaps on asset-backed securities  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Financial and Nonfinancial Liabilities, Fair Value Disclosure $ (2,000)
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.229
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.229
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.229
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.086
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.086
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Default Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.086
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.123
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.123
Valuation, Income Approach | Credit default swaps on asset-backed securities | Measurement Input, Projected Collateral Recoveries | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Derivative Liability, Measurement Input 0.123
Valuation, Income Approach | Total return swaps  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Financial and Nonfinancial Liabilities, Fair Value Disclosure $ 54,000
Valuation, Income Approach | Total return swaps | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.227
Valuation, Income Approach | Total return swaps | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.227
Valuation, Income Approach | Total return swaps | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.227
Valuation, Income Approach | HECM loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 11,015,347,000
Valuation, Income Approach | HECM loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.028
Valuation, Income Approach | HECM loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.063
Valuation, Income Approach | HECM loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.042
Valuation, Income Approach | HECM loans | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.017
Valuation, Income Approach | HECM loans | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.393
Valuation, Income Approach | HECM loans | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.077
Valuation, Income Approach | Mortgage servicing rights  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 30,192,000
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.174
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.174
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.174
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.103
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.426
Valuation, Income Approach | Mortgage servicing rights | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Servicing Asset, Measurement Input 0.146
Valuation, Income Approach | Loan commitments  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 10,207,000
Valuation, Income Approach | Loan commitments | Measurement Input pullthrough rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.660
Valuation, Income Approach | Loan commitments | Measurement Input pullthrough rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.945
Valuation, Income Approach | Loan commitments | Measurement Input pullthrough rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.695
Valuation, Income Approach | Loan commitments | measurement input cost to originate loan | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.038
Valuation, Income Approach | Loan commitments | measurement input cost to originate loan | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.108
Valuation, Income Approach | Loan commitments | measurement input cost to originate loan | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Commitments, Measurement Input 0.054
Valuation, Income Approach | HMBS-related obligations  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ (10,765,668,000)
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.026
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.061
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.040
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.069
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.393
Valuation, Income Approach | HMBS-related obligations | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Debt instrument, measurement input 0.076
Valuation, Income Approach | HECM buyout loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 41,526,000
Valuation, Income Approach | HECM buyout loans | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 1 month
Valuation, Income Approach | HECM buyout loans | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 153 months 24 days
Valuation, Income Approach | HECM buyout loans | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 21 months 6 days
Valuation, Income Approach | HECM buyout loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.052
Valuation, Income Approach | HECM buyout loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.114
Valuation, Income Approach | HECM buyout loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.085
Valuation, Income Approach | Forward MSR-related Investments  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 72,824,000
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.095
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.095
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.095
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.050
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.050
Valuation, Income Approach | Forward MSR-related Investments | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Forward MSR-related Investments, Value Input 0.050
Valuation, Income Approach | Loan Purchase Commitments  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Financial and Nonfinancial Liabilities, Fair Value Disclosure $ (6,443,000)
Valuation, Income Approach | Agency Interest Only RMBS  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 6,051,000
Valuation, Income Approach | Agency Interest Only RMBS | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.162
Valuation, Income Approach | Agency Interest Only RMBS | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.965
Valuation, Income Approach | Agency Interest Only RMBS | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Securities, measurement input 0.554
Enterprise Value | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 82,960,000
Value of investments excluded from range calculation 600,000
Enterprise Value | Investment in unconsolidated entities | Measurement Input, Net Asset Value  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 266,762,000
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Equity method investment, measurement input 0.4
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Equity method investment, measurement input 2.6
measurement input equity multiple | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Equity method investment, measurement input 2.3
Valuation, Cost Approach | Loan Purchase Commitments | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Purchase Commitments, Measurement Input 0.056
Valuation, Cost Approach | Loan Purchase Commitments | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Purchase Commitments, Measurement Input 0.070
Valuation, Cost Approach | Loan Purchase Commitments | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loan Purchase Commitments, Measurement Input 0.061
Including amounts excluded from range calculation | Investment in unconsolidated entities | Measurement Input, Equity Price-to-Book | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Equity method investment, measurement input 2.3
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 588,028,000
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.070
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.106
Performing and/or Re-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.087
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 1,977,901,000
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.002
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.244
Performing and/or Re-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.066
Securitized loans [Member] | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 1,619,364,000
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 1,550,394,000
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.50
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 100.00
Securitized loans [Member] | Valuation, Market Approach | Residential mortgage loans | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 90.99
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 1,633,568,000
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Quoted Price | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 89.94
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Quoted Price | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 113.27
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Quoted Price | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 108.01
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.050
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.079
Securitized loans [Member] | Valuation, Market Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.055
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 68,970,000
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.267
Securitized loans [Member] | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.064
Non-performing | Valuation, Income Approach | Commercial mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 35,168,000
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 2 months
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 8 months
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 4 months
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.085
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.133
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.095
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount $ 0.800
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount 1.000
Non-performing | Valuation, Income Approach | Commercial mortgage loans | Measurement Input recovery amount | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount 0.988
Non-performing | Valuation, Income Approach | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 150,900,000
Non-performing | Valuation, Income Approach | Residential mortgage loans | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 3 months 6 days
Non-performing | Valuation, Income Approach | Residential mortgage loans | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 107 months 3 days
Non-performing | Valuation, Income Approach | Residential mortgage loans | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Investment, measurement input, recovery time 21 months 3 days
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.004
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 1.102
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.076
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input recovery amount | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount $ 0.005
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input recovery amount | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount 2.572
Non-performing | Valuation, Income Approach | Residential mortgage loans | Measurement Input recovery amount | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input, Recovery Amount 0.878
Non-performing securitized residential mortgage loans [Member] | Valuation, Income Approach | Residential mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value 61,900,000
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Fair value $ 299,745,000
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.058
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.100
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Discount Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.071
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Prepayment Rate | Minimum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.069
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Prepayment Rate | Maximum  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.555
Unsecuritized loans | Valuation, Income Approach | Proprietary reverse mortgage loans | Measurement Input, Prepayment Rate | Weighted Average  
Fair Value Measurements Inputs and Valuation Techniques [Line Items]  
Loans, Measurement Input 0.128