Notes Receivable and Current Expected Credit Losses - Additional Information (Details)				1 Months Ended				3 Months Ended	12 Months Ended
	Dec. 30, 2022 USD ($)	Oct. 03, 2022 USD ($)	Dec. 21, 2018 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Feb. 28, 2022 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Mar. 23, 2022 USD ($)	Sep. 30, 2021 USD ($)	Apr. 01, 2021 USD ($)	May 31, 2020 USD ($)	Apr. 19, 2019 USD ($)	Oct. 31, 2018 USD ($)
Notes Receivable
Notes receivable paydowns									$ 35,848,000	$ 42,301,000	$ 16,340,000
Guaranty liabilities				$ 899,000					899,000	1,243,000
Allowance for notes receivable and unfunded commitments				1,630,000				$ 2,584,000	1,630,000	1,004,000	2,584,000
Allowance related to unfunded commitments				338,000				0	338,000	10,000	0
Allowances for loan losses				1,292,000				2,584,000	1,292,000	994,000	2,584,000
Total notes receivable				136,039,000					136,039,000	126,429,000
Financing receivable, nonaccrual				0				13,600,000	0		13,600,000
Financing receivable, interest not recognized											$ 5,100,000
Mezzanine Loan
Notes Receivable
Notes receivable				112,284,000					112,284,000	118,946,000
Maximum loan commitment				169,504,000					$ 169,504,000
Number of loans | loan									3
Interlock Commercial | Mezzanine Loan
Notes Receivable
Notes receivable				86,584,000					$ 86,584,000	95,379,000
Maximum commitment, excluding accrued interest reserves			$ 67,000,000
Maximum loan commitment			$ 95,000,000	$ 107,000,000					$ 107,000,000				$ 107,000,000
Interest rate			15.00%	15.00%					15.00%
Financing receivable term			24 months
Financing receivable term extension option			5 years
Guarantor obligations of the senior construction loan (up to)																$ 30,700,000
Additional funds available						$ 7,500,000									$ 8,000,000
Exit fee								6,500,000
Exit fee revenue recognized								4,900,000
Principal amount													$ 70,100,000
Paydown received on note receivable				$ 400,000	$ 2,700,000	700,000	$ 13,500,000
Notes receivable paydowns					1,000,000	200,000	11,100,000
Proceeds from interest received					$ 1,700,000	$ 500,000	$ 2,400,000
Interlock Commercial | Mezzanine Loan | Minimum
Notes Receivable
Exit fee								6,500,000
Interlock Commercial | Mezzanine Loan | Maximum
Notes Receivable
Exit fee								$ 7,500,000
Interlock Commercial | Bridge Loan | Mezzanine Loan
Notes Receivable
Notes receivable																	$ 4,000,000
Nexton Multifamily
Notes Receivable
Prepayment premium									$ 2,700,000
Nexton Multifamily | Mezzanine Loan
Notes Receivable
Notes receivable				0					0	23,567,000
Maximum loan commitment				$ 22,315,000					$ 22,315,000					$ 22,300,000
Interest rate				11.00%					11.00%					11.00%
Paydown received on note receivable	$ 28,900,000
Minimum return	6,600,000
Proceeds from interest received	$ 3,900,000
Guaranty liabilities				$ 900,000					$ 900,000	1,200,000
City Park 2 | Mezzanine Loan
Notes Receivable
Notes receivable				19,062,000					19,062,000	0
Maximum loan commitment				$ 20,594,000					$ 20,594,000			$ 20,600,000
Interest rate				13.00%					13.00%			13.00%
Solis Gainesville II | Mezzanine Loan
Notes Receivable
Notes receivable				$ 6,638,000					$ 6,638,000	0
Maximum loan commitment		$ 19,600,000		$ 19,595,000					$ 19,595,000
Interest rate		14.00%		14.00%					14.00%
Minimum interest		$ 5,900,000
Constellation Energy Building | Constellation Energy Building note receivable
Notes Receivable
Notes receivable				$ 12,834,000					$ 12,834,000	$ 0
Interest rate, nonacrrual									3.00%