Related Party Transactions - Schedule of Balance Sheet of Related Party Transaction (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Carrying value	[1]	$ 327,793	$ 355,178
Due from related parties		19,153	20,899
Beneficial interests in securitization trusts
Related Party Transaction [Line Items]
Carrying value		139,249	139,588
Mortgage Loans, Net | Gaea Real Estate Corp.
Related Party Transaction [Line Items]
Due from related parties			21
Mortgage Loans, Net | 2019-C | Purchase of Mortgage Loans
Related Party Transaction [Line Items]
Due from related parties			152,883
Management fee payable | Thetis Asset Management LLC
Related Party Transaction [Line Items]
Due to related parties		2,424	2,279
Prepaid expenses and other assets
Related Party Transaction [Line Items]
Due from related parties		1,215	1,211
Prepaid expenses and other assets | Servicer
Related Party Transaction [Line Items]
Due from related parties		15	12
Prepaid expenses and other assets | Servicer | Affiliate loan receivable and interest
Related Party Transaction [Line Items]
Due from related parties		3,522	3,509
Accrued expenses and other liabilities
Related Party Transaction [Line Items]
Due to related parties		23
Accrued expenses and other liabilities | Gregory
Related Party Transaction [Line Items]
Due to related parties		69
Accrued expenses and other liabilities | Servicer
Related Party Transaction [Line Items]
Due to related parties		16	78
Accrued expenses and other liabilities | Gaea Real Estate Corp.
Related Party Transaction [Line Items]
Due to related parties		8
Receivable from servicer | Servicer | Receivable from servicer
Related Party Transaction [Line Items]
Due from related parties		$ 19,153	$ 20,899

[1] As of March 31, 2022, Investments in securities at fair value include an amortized cost basis of $336.6 million and a net unrealized loss of $8.8 million. As of December 31, 2021, Investments in securities at fair value include an amortized costs basis of $354.2 million and net unrealized gains $1.0 million.