Repurchase Agreements, Loan Participations Sold, Notes Payable and Secured Term Loan, Net - Summary of Notes Payable (Details) - USD ($)					1 Months Ended		12 Months Ended
		Mar. 12, 2021	Jan. 31, 2021	Jan. 05, 2021	Jan. 31, 2022	Jun. 02, 2021	Dec. 31, 2021		Dec. 31, 2020
Debt Instrument [Line Items]
Contractual Maturity Date					Jul. 05, 2022	Feb. 09, 2024
Maximum Extension Date					Jan. 04, 2023
Outstanding principal balance									$ 500,000,000
Carrying value							$ 167,744,000	[1]	516,484,000	[2]
Loan held by company							$ 420,844,000	[1]	888,232,000	[2]
Notes Payable [Member]
Debt Instrument [Line Items]
Contractual Maturity Date		Oct. 01, 2021					Jan. 04, 2022	[3],[4]
Maximum Extension Date		Jan. 04, 2022	Jul. 30, 2021	Apr. 01, 2021			Jan. 04, 2022	[3],[4]
Outstanding principal balance							$ 48,000,000	[3],[4]	305,294,000	[5]
Carrying value							48,000,000	[3],[4]	303,515,000	[5]
Loan held by company	[6]						$ 116,512,000	[3],[4]	$ 540,204,000	[5]
Notes Payable One
Debt Instrument [Line Items]
Contractual Maturity Date	[7]								Jan. 04, 2021
Maximum Extension Date	[7]								Apr. 01, 2021
Outstanding principal balance	[7]								$ 52,938,000
Carrying value	[7]								52,938,000
Loan held by company	[6],[7]								$ 116,514,000
Notes Payable Two
Debt Instrument [Line Items]
Contractual Maturity Date									Aug. 02, 2022
Maximum Extension Date									Aug. 02, 2023
Outstanding principal balance									$ 99,579,000
Carrying value									98,553,000
Loan held by company	[6]								$ 132,761,000
Notes Payable Three
Debt Instrument [Line Items]
Contractual Maturity Date	[8]								Jan. 31, 2021
Maximum Extension Date	[8]								Jul. 30, 2021
Outstanding principal balance	[8]								$ 40,000,000
Carrying value	[8]								39,950,000
Loan held by company	[6],[8]								$ 67,146,000
Notes Payable Four
Debt Instrument [Line Items]
Contractual Maturity Date	[9]								Jul. 30, 2021
Maximum Extension Date	[9]								Jul. 30, 2023
Outstanding principal balance	[9]								$ 92,777,000
Carrying value	[9]								92,322,000
Loan held by company	[6],[9]								$ 117,165,000
Notes Payable Five
Debt Instrument [Line Items]
Contractual Maturity Date									Jan. 15, 2022
Maximum Extension Date									Jan. 15, 2022
Outstanding principal balance									$ 20,000,000
Carrying value									19,752,000
Loan held by company	[6]								$ 106,618,000

[1] This financing has a LIBOR floor of 1.85%.

[2] Weighted average interest rate as of December 31, 2020 was 5.09%. Weighted average is based on outstanding principal as of December 31, 2020.

[3] Weighted average interest rate as of December 31, 2021 was LIBOR plus 4.00%. One-month LIBOR as of December 31, 2021 was 0.10%. This financing has a LIBOR floor of 2.43%. Weighted average is based on outstanding principal as of December 31, 2021.

[4] In January 2022, the initial maturity was extended to July 5, 2022 and the maximum maturity date was extended to January 4, 2023.

[5] Weighted average interest rate as of December 31, 2020 was LIBOR plus 3.44%. One-month LIBOR as of December 31, 2020 was 0.14%. Weighted average is based on outstanding principal as of December 31, 2020.

[6] Includes all cash reserve balances held by the servicer.

[7] On January 5, 2021, the note was extended to the maximum extended maturity date of April 1, 2021. On March 12, 2021, the Company entered into an agreement to extend the contractual maturity date to October 1, 2021 and the maximum extended maturity date to January 4, 2022.

[8] On January 31, 2021, the note was extended to the maximum extended maturity date of July 30, 2021.

[9] The Company has guaranteed a portion of this note payable. The Company’s maximum exposure is limited to $20.0 million.