Combined Guarantor Subsidiaries - Mortgage and Other Notes Receivable - Summary (Details) - USD ($)		6 Months Ended	12 Months Ended
		Jun. 30, 2020	Dec. 31, 2019
Mortgage and Other Notes Receivable [Line Items]
Balance		$ 2,729,000	$ 4,662,000
Mortgage Receivable
Mortgage and Other Notes Receivable [Line Items]
Interest Rate (as a percent)		3.48%
Balance		$ 1,100,000	2,637,000
Other Notes Receivable
Mortgage and Other Notes Receivable [Line Items]
Balance		1,629,000	2,025,000
Guarantor Subsidiaries
Mortgage and Other Notes Receivable [Line Items]
Balance		73,786,000	75,016,000
Guarantor Subsidiaries | Mortgage Receivable
Mortgage and Other Notes Receivable [Line Items]
Balance		$ 73,786,000	$ 73,786,000
Guarantor Subsidiaries | Mortgage Receivable | The Promenade
Mortgage and Other Notes Receivable [Line Items]
Maturity Date	[1]	2020-12
Interest Rate (as a percent)	[1]	5.00%	5.00%
Balance	[1]	$ 47,514,000	$ 47,514,000
Guarantor Subsidiaries | Mortgage Receivable | Hamilton Corner
Mortgage and Other Notes Receivable [Line Items]
Maturity Date	[1]	2020-08
Interest Rate (as a percent)	[1]	5.67%	5.67%
Balance	[1]	$ 14,295,000	$ 14,295,000
Guarantor Subsidiaries | Mortgage Receivable | The Terrace
Mortgage and Other Notes Receivable [Line Items]
Maturity Date	[1]	2020-12
Interest Rate (as a percent)	[1]	7.25%	7.25%
Balance	[1]	$ 11,977,000	$ 11,977,000
Guarantor Subsidiaries | Other Notes Receivable
Mortgage and Other Notes Receivable [Line Items]
Balance		$ 73,786,000	$ 75,016,000
Guarantor Subsidiaries | Other Notes Receivable | Community improvement district
Mortgage and Other Notes Receivable [Line Items]
Maturity Date		2028-08
Interest Rate (as a percent)			6.75%
Balance			$ 1,230,000

[1] The mortgaged property is owned by an entity that is controlled by the Operating Partnership and included in the Operating Partnership's condensed consolidated financial statements. The mortgage note receivable is interest only.