Commitments and Contingencies - Additional Information (Details)	3 Months Ended
	Jun. 30, 2019 ft²	Mar. 31, 2019 USD ($)	Dec. 31, 2016 USD ($)
Commitments And Contingencies [Line Items]
Lease expiration date		Jan. 03, 2020
Operating leases, future minimum payments, due in 2019		$ 15,288
Millbrook, NY
Commitments And Contingencies [Line Items]
Estimate for expansion relating to construction cost		As of March 31, 2019, development costs for this project has been capitalized and are reflected in real estate assets, net on the Company’s consolidated balance sheet.
Millbrook, NY | Scenario Forecast
Commitments And Contingencies [Line Items]
Gross square feet of traditional drive-up storage units and all-climate-controlled units | ft²	16,500
Tuxis
Commitments And Contingencies [Line Items]
Additional cash payment			$ 900,000