Combined Guarantor Subsidiaries - Summary of Significant Accounting Policies - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Restricted cash related to mortgage escrows	[1]	$ 24,949,000	$ 31,254,000	$ 24,949,000	$ 31,254,000
Net deferred financing costs		19,490,000		19,490,000
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Amortization of intangible assets		665,000	536,000	1,291,000	1,262,000
Estimated total net amortization expense of intangible assets for remainder of 2019		709,000		709,000
Estimated total net amortization expense of intangible assets in 2020		1,166,000		1,166,000
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		101,000	210,000	196,000	398,000
Restricted cash related to mortgage escrows		3,434,000	3,079,000	3,434,000	3,079,000	$ 7,139,000
Net deferred financing costs		237,000		237,000		361,000
Amortization expense related to deferred financing costs		62,000	$ 62,000	124,000	$ 139,000
Accumulated amortization of deferred financing costs		1,216,000		1,216,000		$ 1,092,000
Income tax provision		$ 0		$ 0
Concentration risk (less than)			5.10%
Building | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment				40 years
Minimum | Improvements | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment				10 years
Minimum | Equipment and Fixtures | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment				7 years
Maximum | Improvements | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment				20 years
Maximum | Equipment and Fixtures | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Useful life of property, plant and equipment				10 years
Customer Concentration Risk | Sales Revenue, Net | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Concentration risk (less than)		10.00%

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