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Equity incentive plan (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
Equity incentive plan (Narrative) (Details) - USD ($)	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2022	Jul. 31, 2021
Employee Stock Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options granted during period
Options granted during period, price per share
Compensation expense related to stock options	$ 15,000	$ 35,000	$ 5,000	$ 11,000
Unrecognized compensation cost	16,000		16,000
Unrecognized compensation cost, recognition period				10 months 24 days
Aggregate intrinsic value of options expected to vest	1,901,000		1,901,000
Aggregate intrinsic value of options exercisable	$ 1,825,000		$ 1,825,000
Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares available for issuance	442,060		442,060