Notes Receivable (Details)	1 Months Ended	12 Months Ended
	Apr. 30, 2018	Dec. 31, 2019 USD ($) property	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018	Aug. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		$ 4,614,000	$ 11,159,000
Interest receivable (net prepaid interest)		565,000	947,000
Provision for loan receivable		(412,000)	(229,000)
Total notes and interest receivable		4,767,000	11,877,000
Notes receivable		4,600,000	11,700,000
Mortgage loan
Balance at beginning of year		11,159,000	9,350,000	$ 2,780,000
New mortgage loans and additional advances on existing loans		1,781,000	6,662,000	7,372,000
Additions during year		12,940,000	16,012,000	10,152,000
Collection of principal		8,285,000	4,853,000	802,000
Foreclosure		41,000
Balance at end of year		4,614,000	11,159,000	$ 9,350,000
Mortgage Note Maturing on 1/15/2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		1,804,000	1,840,000
Note Receivable Maturing on 3/16/2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		$ 234,000	234,000
Note Receivable Maturing on 3/16/2022 | Colorado
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of additional properties | property		2
Mortgage Note Maturing on 3/16/2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		$ 2,145,000	2,145,000
Interest rate (as a percent)	7.50%				6.50%
Loan fee	1.00%
Mortgage Note Maturing on 3/16/2022 | Colorado
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of additional properties | property		2
Mortgage Note Maturing on 3/1/2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal			1,647,000
Mortgage Note Maturing on 8/19/2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal			5,125,000
Mortgage Note Maturing on 12/31/2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		$ 62,000	62,000
Line of Credit Maturing on 11/15/2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total outstanding principal		$ 369,000	$ 106,000
FPI Loan Program | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal amounts						$ 100,000
FPI Loan Program | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt instrument, term		3 years