Deferred fee plan (Details) - USD ($)	12 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trustee fee expense	$ 781,000
Dividends payable	2,018,000	$ 2,046,000	$ 4,582,000
Deferred Fee Plan [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trustee fee expense	$ 752,200	1,204,000	$ 1,101,000
Shares issued	39,350
Deferred trustee fees	$ 5,224,000	$ 5,163,000
Deferred accrued interest	$ 3,854,000
Interest rate on any deferred fee	9.00%
Basis spread on any deferred fee (percentage)	1.50%
Term of distribution to participants	10 years
Dividends payable	$ 29,000