Share repurchases (Details) - USD ($)			12 Months Ended
	Mar. 20, 2015	Feb. 17, 2015	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Equity [Abstract]
Number of shares authorized to repurchase		100,000
Number of shares repurchased	94,302				94,302
Shares repurchased, value	$ 2,168,946				$ 2,169,000
Stock repurchased price (per share)	$ 23.00	$ 23.00