Mortgage Loans on Real Estate - Schedule of Loans (UPB) Collateralized by Real Estate (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022		Dec. 31, 2021
Residential Real Estate
Debt Instrument [Line Items]
Unpaid Principal Balance	[1],[2]	$ 1,851,539	[3]	$ 1,312,094	[4]
Nonaccrual Unpaid Principal Balance		$ 184,633	[3]	$ 171,640	[4]
Residential Real Estate | Less Than One Million
Debt Instrument [Line Items]
Final Maturity Date	[3]	Jan. 01, 2053		Jan. 01, 2052
Unpaid Principal Balance	[1],[2],[3]	$ 1,374,726		$ 987,069
Nonaccrual Unpaid Principal Balance	[3]	$ 127,125		$ 127,214
Residential Real Estate | Less Than One Million | Minimum
Debt Instrument [Line Items]
Interest Rate	[3]	4.00%		4.00%
Residential Real Estate | Less Than One Million | Maximum
Debt Instrument [Line Items]
Interest Rate	[3]	13.50%		13.50%
Residential Real Estate | One Million And More
Debt Instrument [Line Items]
Final Maturity Date	[3]	Jan. 01, 2053		Jan. 01, 2052
Unpaid Principal Balance	[1],[2],[3]	$ 476,813		$ 325,025
Nonaccrual Unpaid Principal Balance	[3]	$ 57,508		$ 44,426
Residential Real Estate | One Million And More | Minimum
Debt Instrument [Line Items]
Interest Rate	[3]	4.00%		4.00%
Residential Real Estate | One Million And More | Maximum
Debt Instrument [Line Items]
Interest Rate	[3]	11.50%		11.50%
Commercial Real Estate
Debt Instrument [Line Items]
Unpaid Principal Balance	[1],[2]	$ 1,660,947	[4]	$ 1,275,127	[3]
Nonaccrual Unpaid Principal Balance		$ 108,156	[4]	$ 101,460	[3]
Commercial Real Estate | Less Than One Million
Debt Instrument [Line Items]
Final Maturity Date	[4]	Jan. 01, 2053		Jan. 01, 2052
Unpaid Principal Balance	[1],[2],[4]	$ 1,196,378		$ 969,599
Nonaccrual Unpaid Principal Balance	[4]	$ 69,763		$ 73,039
Commercial Real Estate | Less Than One Million | Minimum
Debt Instrument [Line Items]
Interest Rate	[4]	4.00%		3.10%
Commercial Real Estate | Less Than One Million | Maximum
Debt Instrument [Line Items]
Interest Rate	[4]	13.70%		13.00%
Commercial Real Estate | One Million And More
Debt Instrument [Line Items]
Final Maturity Date	[4]	Jan. 01, 2053		Jan. 01, 2052
Unpaid Principal Balance	[1],[2],[4]	$ 464,569		$ 305,528
Nonaccrual Unpaid Principal Balance	[4]	$ 38,393		$ 28,421
Commercial Real Estate | One Million And More | Minimum
Debt Instrument [Line Items]
Interest Rate	[4]	4.00%		4.00%
Commercial Real Estate | One Million And More | Maximum
Debt Instrument [Line Items]
Interest Rate	[4]	11.70%		10.20%
Real Estate
Debt Instrument [Line Items]
Unpaid Principal Balance	[1],[2]	$ 3,512,486		$ 2,587,221
Nonaccrual Unpaid Principal Balance		$ 292,789		$ 273,100

[1] As of December 31, 2022 and 2021, $168.4 million and $155.1 million, respectively, of the total UPB were interest-only loans with interest payable monthly and the principal payable at maturity.

[2] The aggregate cost of the Company’s loan portfolio for Federal income tax purposes was $3,553,379 and $2,621,093 as of December 31, 2022 and 2021, respectively.

[3] The principal and interest on the 1-4 unit residential mortgage loans is payable monthly over the life of the loan to maturity. These loans generally contain a 3% prepayment penalty provision if the loan is prepaid within the first 3 years.

[4] The principal and interest on the traditional commercial mortgage loans is payable monthly over the life of the loan to maturity. These loans generally contain a 5% prepayment penalty provision if the loan is prepaid within the first 3 years.