Combined Guarantor Subsidiaries - Summary of Significant Accounting Policies - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Restricted cash related to mortgage escrows	[1]	$ 28,511,000	$ 30,769,000		$ 28,511,000	$ 30,769,000
Net deferred financing costs		17,640,000			17,640,000
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Amortization of intangible assets		505,000	391,000		1,796,000	1,653,000
Estimated total net amortization expense of intangible assets for remainder of 2019		517,000			517,000
Estimated total net amortization expense of intangible assets in 2020		1,603,000			1,603,000
Estimated total net amortization expense of intangible assets in 2021		1,212,000			1,212,000
Estimated total net amortization expense of intangible assets in 2022		991,000			991,000
Estimated total net amortization expense of intangible assets in 2023		680,000			680,000
Estimated total net amortization expense of intangible assets in 2024		614,000			614,000
Interest expense capitalized		157,000	155,000		353,000	553,000
Restricted cash related to mortgage escrows		4,127,000	3,182,000		4,127,000	3,182,000	$ 7,139,000
Net deferred financing costs		174,000			174,000		361,000
Amortization expense related to deferred financing costs		62,000	$ 62,000		186,000	$ 201,000
Accumulated amortization of deferred financing costs		1,278,000			1,278,000		$ 1,092,000
Income tax provision		$ 0			$ 0
Customer Concentration Risk | Sales Revenue, Net | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Concentration risk (less than)		10.00%		10.00%
Building | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment					40 years
Improvements | Minimum | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment					10 years
Improvements | Maximum | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment					20 years
Equipment and Fixtures | Minimum | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment					7 years
Equipment and Fixtures | Maximum | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment					10 years

[1] Included in intangible lease assets and other assets in the condensed consolidated balance sheets.