Investments in Real Estate - Investments in Existing Properties (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Investments in real estate properties
Improvements	$ 70,453,710
Investments in Existing Properties
Investments in real estate properties
Improvements	17,900,000	$ 12,700,000
Re-leasing costs	3,900,000	1,600,000
Recurring capital expenditures	1,100,000	912,000
Nonrecurring building improvements	$ 12,900,000	$ 10,200,000