Intangibles, net - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Finite Lived Intangible Assets And Liabilities [Line Items]
Amortization expense on intangible assets	$ 200,000		$ 600,000
Amortization of intangible liabilities		$ 0		$ 0
Property Operating Expenses
Finite Lived Intangible Assets And Liabilities [Line Items]
Amortization expense on intangible assets	10,000		30,000
Depreciation And Amortization
Finite Lived Intangible Assets And Liabilities [Line Items]
Amortization expense on intangible assets	200,000	$ 100,000	600,000	$ 300,000
Rental Income from Operating Leases
Finite Lived Intangible Assets And Liabilities [Line Items]
Amortization of intangible liabilities	$ 8,000		$ 23,000