Management agreement, fees and transactions with related party (Details) - USD ($)		6 Months Ended	12 Months Ended
	Oct. 31, 2006	May 07, 2008	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013
Related Party Transaction [Line Items]
Asset management fees			$ 2,046,000	$ 2,000,000	$ 1,968,000
Total construction financing, including other members			14,460,000
Secured loans receivable to noncontrolling interest					2,128,000
Amount of the capital call			8,700,000
Payment of capital call			8,700,000
Managing Agent Hekemian & Co [Member]
Related Party Transaction [Line Items]
Asset management fees			1,930,000	1,899,000	1,866,000
Leasing commissions and reimbursement of operating expenses			577,000	465,000	673,000
Leasing commissions					396,000
Insurance commissions			164,000	166,000	133,000
Sales commissions			880,000
Maximum advances to employees		$ 2,000,000	4,000,000
Accounts Payable			$ 181,000	163,000
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			532,000	538,000	642,000
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]
Development fees paid			1,000,000	1,000,000
Redevelopment fees			443,000	1,546,000	1,998,000
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	$ 46,000
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			$ 886,000	$ 732,000
Ownership by parent (percentage)			60.00%
Ownership by noncontrolling owners (percentage)			40.00%