Subsequent Events - Additional Information (Details) $ in Millions		Oct. 25, 2019 USD ($)	Oct. 23, 2019 ft² Unit	Oct. 04, 2019 USD ($)	Sep. 30, 2019 ft²
West Henrietta Property Acquisition
Subsequent Event [Line Items]
Leasable square foot property | ft²	[1]				46,850
Subsequent Event | Rights Offerings | Common Stock | Maximum
Subsequent Event [Line Items]
Newly issued shares | $		$ 11.6
Subsequent Event | West Henrietta Property Acquisition | New York
Subsequent Event [Line Items]
Business acquisition price | $				$ 6.2
Subsequent Event | Erie Station Storage, LLC | West Henrietta Property Acquisition | New York
Subsequent Event [Line Items]
Business acquisition agreement date				Oct. 04, 2019
Subsequent Event | Edmond Property Third-Party Management | Oklahoma
Subsequent Event [Line Items]
Leasable square foot property | ft²			134,318
Number of climate-controlled and non-climate-controlled units | Unit			618

[1] Does not include a potential expansion of the property of up to approximately 7,300 net leasable square feet that we may undertake if the acquisition of the property is completed.