Fair Value of Financial Instruments - Fair Value Methodology (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	$ 739,189	$ 795,894
Purchases excluded from level 2 fair value	523	215
Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	5,702,253	4,880,321
Purchases excluded from level 2 fair value	39,000
Discounted cash flow | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	537,510	546,675
Discounted cash flow | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	5,634,049	4,857,587
Liquidation model | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	201,679	249,219
Simple average amount	472	457
Liquidation model | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Purchased loans	$ 68,204	$ 22,734
Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	(3.10%)	(5.40%)
Liquidation timeline (in years)	1 month 6 days	1 month 6 days
Fair value inputs, value of underlying property	$ 28	$ 28
Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	(3.20%)	(1.00%)
Liquidation timeline (in years)	9 months 18 days	9 months 18 days
Fair value inputs, value of underlying property	$ 44	$ 50
Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	12.00%	59.70%
Liquidation timeline (in years)	4 years 6 months	4 years 6 months
Fair value inputs, value of underlying property	$ 4,720	$ 4,000
Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	8.70%	10.70%
Liquidation timeline (in years)	4 years 2 months 12 days	4 years 2 months 12 days
Fair value inputs, value of underlying property	$ 4,500	$ 2,850
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.063	0.063
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.065	0.056
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.110	0.100
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.455	0.227
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.071	0.070
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.076
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.080	0.078
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.291	0.335
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.419	0.448
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.076	0.089
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.092	0.079
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.307	0.524
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.260	0.194
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.028	0.037
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.009	0.008
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.000	0.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	1.000	1.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	1.000	1.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.101	0.113
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input	0.110	0.073
Annual change in home prices | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	3.50%	6.90%
Annual change in home prices | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, annual change in home prices	2.20%	3.20%
Liquidation timeline (in years) | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liquidation timeline (in years)	1 year 10 months 24 days	1 year 10 months 24 days
Liquidation timeline (in years) | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liquidation timeline (in years)	1 year 9 months 18 days	1 year 10 months 24 days
Current value of underlying properties | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Nonperforming
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, value of underlying property	$ 787	$ 743
Current value of underlying properties | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average | Performing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, value of underlying property	$ 1,607	$ 1,319