Deferred fee plan (Details) - USD ($)	9 Months Ended		12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Oct. 31, 2021
Deferred Compensation Arrangement with Individual, Excluding Share-Based Payments and Postretirement Benefits [Line Items]
Dividends payable		$ 343,000	$ 686,000
Deferred Fee Plan [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-Based Payments and Postretirement Benefits [Line Items]
Trustee fee expense	126,600	356,000
Deferred trustee fees	91,300	$ 332,000
Deferred accrued interest	$ 951,000		1,021,000
Term of distribution to participants	10 years
Shares issued	5,163	20,328
Dividends payable	$ 35,300	$ 24,000
Cumulative fees	$ 1,366,000		$ 1,454,000