Investments in Real Estate - Investments in Existing Properties Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Investments in real estate properties
Capitalized costs on existing portfolio	$ 3,997	$ 4,710
Investments in existing properties
Investments in real estate properties
Capitalized costs on existing portfolio	4,300	4,400
Re-leasing costs	827	1,100
Recurring capital expenditures	51	23
Non-recurring building improvements	$ 3,400	$ 3,300