Real Estate Assets - Additional Information (Details) - Millbrook, NY	12 Months Ended
Dec. 31, 2019 ft²
Real Estate Properties [Line Items]
Gross square feet of traditional drive-up storage units and all-climate-controlled units	16,500
Estimate for expansion relating to construction cost	As of December 31, 2019, development costs for this project have been capitalized and are reflected in real estate assets, net on the Company’s consolidated balance sheets. Construction of the expansion was completed in the first quarter of 2020.

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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