Notes Receivable and Current Expected Credit Losses (Summary of Mezzanine Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 23, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable guarantee premium	$ 1,345		$ 1,243
Allowance for credit losses	(1,452)		(994)
Total notes receivable	139,383		126,429
Mezzanine loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	119,201		118,946
Maximum loan commitment	149,909
Mezzanine loan | City Park 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	8,014		0
Maximum loan commitment	$ 20,594	$ 20,600
Interest rate	13.00%	13.00%
Mezzanine loan | Interlock Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	$ 86,334		95,379
Maximum loan commitment	$ 107,000
Interest rate	15.00%
Mezzanine loan | Nexton Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	$ 24,853		23,567
Maximum loan commitment	$ 22,315
Interest rate	11.00%
Mezzanine loan | Exelon building
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate	3.00%
Exelon note receivable | Exelon building
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	$ 12,834		0
Other notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	7,455		$ 7,234
Unfunded loan commitment | Other liabilities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ (500)