Organization and significant accounting policies (Narrative) (Details) - USD ($)	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Advertising costs	$ 386,000	$ 257,000	$ 162,000
Amortization of mortgage costs and leasing commissions	$ 1,298,000	$ 543,000	$ 419,000