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Consulting fees.

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Management agreement, fees and transactions with related party (Details) - USD ($)	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Feb. 28, 2018	Apr. 30, 2019	Oct. 31, 2018	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018	Oct. 30, 2013
Related Party Transaction [Line Items]
Asset management fees		$ 648,000		$ 649,000	$ 1,285,000	$ 1,260,000
Consulting fees		15,000		4,200	30,000	4,200
Secured loans receivable		4,000,000	$ 4,000,000		4,000,000
Due to affiliate		5,560,000	5,417,000		$ 5,560,000
Minimum [Member]
Related Party Transaction [Line Items]
Asset management fees percentage rate					4.00%
Maximum [Member]
Related Party Transaction [Line Items]
Asset management fees percentage rate					5.00%
Damascus Centre [Member]
Related Party Transaction [Line Items]
Secured notes outstanding			1,870,000
Principal amount on notes			1,451,000
Accrued interest payable			419,000
Unpaid accrued interest		$ 958,000	862,000		$ 958,000
Grande Rotunda, LLC [Member]
Related Party Transaction [Line Items]
Ownership by noncontrolling owners (percentage)		40.00%			40.00%
Ownership by parent (percentage)		60.00%			60.00%
Due to affiliate		$ 5,600,000			$ 5,600,000
Damascus Centre, LLC [Member]
Related Party Transaction [Line Items]
Ownership by noncontrolling owners (percentage)		30.00%			30.00%
Ownership by parent (percentage)		70.00%			70.00%
Grande Rotunda, LLC [Member]
Related Party Transaction [Line Items]
Due to affiliate			$ 5,400,000
Managing Agent Hekemian & Co [Member]
Related Party Transaction [Line Items]
Asset management fees		$ 636,000		619,000	$ 1,255,000	1,194,000
Leasing commissions and reimbursement of operating expenses		178,000		130,000	311,000	270,000
Sales commissions						522,500
Insurance commissions		20,000		17,000	48,000	49,000
Additional services		131,250		432,500	131,250	1,195,000
Grande Rotunda LLC Loan [Member]
Related Party Transaction [Line Items]
Brokerage fee commissions						400,000
Pierre Towers, LLC [Member]
Related Party Transaction [Line Items]
Brokerage fee commissions						240,000
Line of Credit [Member]
Related Party Transaction [Line Items]
Brokerage fee commissions						32,500
Grande Rotunda LLC [Member]
Related Party Transaction [Line Items]
Fee amount	$ 900,000				1,400,000	45,000	$ 500,000
Affiliated Entity 1 [Member]
Related Party Transaction [Line Items]
Development fees included in accounts payable	900,000
Hekemian and Resources [Member]
Related Party Transaction [Line Items]
Fee amount	$ 900,000
Robert S. Hekemian [Member]
Related Party Transaction [Line Items]
Trustee fees and related interest payable in stock units		54,000		119,000	114,000	255,000
Consulting fee per month					5,000
Consulting fee quarterly installments					15,000
Robert S. Hekemian, Jr. [Member]
Related Party Transaction [Line Items]
Trustee fees and related interest payable in stock units		99,000		27,000	194,000	41,000
Allan Tubin [Member]
Related Party Transaction [Line Items]
Trustee fees and related interest payable in stock units		7,000		0	7,000	0
David Hekemian [Member]
Related Party Transaction [Line Items]
Trustee fees and related interest payable in stock units		$ 16,000		$ 2,000	$ 28,000	$ 2,000