Management agreement, fees and transactions with related party (Details) - USD ($)		6 Months Ended	12 Months Ended
	Oct. 31, 2007	May 07, 2008	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2013
Related Party Transaction [Line Items]
Asset management fees			$ 2,375,000	$ 2,046,000	$ 2,000,000
Total construction financing, including other members			14,460,000
Amount of the capital call			8,700,000
Payment of capital call			8,700,000
Due to affiliate			5,172,000
Managing Agent Hekemian & Co [Member]
Related Party Transaction [Line Items]
Asset management fees			2,216,000	1,930,000	1,899,000
Leasing commissions and reimbursement of operating expenses			1,191,000	577,000	465,000
Insurance commissions			175,000	164,000	166,000
Maximum advances to employees		$ 2,000,000	4,000,000	4,000,000
Accounts Payable			$ 200,000	181,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Development fee (as percentage)			6.375%
Development fees paid			$ 3,000,000			$ 500,000
Fee, to be paid on issuance of certificate of occupancy			900,000
Robert S. Hekemian [Member]
Related Party Transaction [Line Items]
Trustee fee expense			538,000	532,000	538,000
Rotunda 100 [Member]
Related Party Transaction [Line Items]
Secured loans receivable to noncontrolling interest			2,100,000
Amount of the capital call			5,800,000
Payment of capital call			5,800,000
Advance to affiliate			3,700,000
Fee amount			1,400,000
Affiliated Entity 1 [Member]
Related Party Transaction [Line Items]
Redevelopment fees			467,500	443,000	1,546,000
Construction and development costs						$ 1,400,000
Development fees included in accounts payable			900,000	900,000
Robert S. Hekemian, Jr. [Member]
Related Party Transaction [Line Items]
Trustee fee expense			$ 65,000	65,000	$ 65,000
Damascus Centre, LLC [Member]
Related Party Transaction [Line Items]
Ownership by parent (percentage)			70.00%
Ownership by noncontrolling owners (percentage)			30.00%
Sale of interest	$ 3,224,000
Sale of interest, amount financed	$ 1,451,000
Grande Rotunda, LLC [Member]
Related Party Transaction [Line Items]
Aggregate outstanding principal balance			$ 5,451,000	5,451,000
Accrued but unpaid interest			$ 1,068,000	$ 886,000
Ownership by parent (percentage)			60.00%
Ownership by noncontrolling owners (percentage)			40.00%
Due to affiliate			$ 5,172,000