Stock option plan (Schedule of Stock Option Activity) (Details) - Employee Stock Option [Member] - USD ($)				6 Months Ended
	May 03, 2018	Nov. 10, 2016	Sep. 04, 2014	Apr. 30, 2018
No. of Options Outstanding
Options outstanding beginning of period	$ 218,000			$ 267,780
Options granted during period		38,000	246,000
Options forfeited/cancelled during period
Options outstanding end of period				267,780
Options vested and expected to vest				262,280
Options exercisable at end of period				147,940
Weighted Average Exercise Price
Options outstanding beginning of period	$ 18.81			$ 18.81
Options granted during period		$ 21.00	$ 18.45
Options forfeited/cancelled during period
Options outstanding end of period				$ 18.81