Significant Accounting Policies - Cash, Cash Equivalents and Restricted cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Discontinued Operations
Time period within which sale or disposition of properties held for sale is probable	1 year
Cash, Cash Equivalents and Restricted Cash
Cash and cash equivalents	$ 125,530	$ 3,739
Restricted Cash	2,350	2,893
Total cash, cash equivalents and restricted cash	$ 127,880	$ 6,632	$ 40,751	$ 4,150
Restricted Cash, Statement of Financial Position [Extensible Enumeration]	Total cash, cash equivalents and restricted cash
FSP Monument Circle LLC
Cash, Cash Equivalents and Restricted Cash
Total cash, cash equivalents and restricted cash	$ 2,167