Intangible assets (Detail) - USD ($) $ in Thousands	Jul. 31, 2017	Oct. 31, 2016
Intangible Assets [Line Items]
Amortizable intangible assets, net	$ 3,177	$ 3,619
Non-amortizable intangible assets, trade marks	1,237	1,237
Non-compete agreements (estimated lives 3 - 5 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	310	310
Amortizable intangible assets, accumulated amortization	(301)	(273)
Amortizable intangible assets, net	9	37
Customer relationships (estimated lives 7 - 15 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	5,099	5,099
Amortizable intangible assets, accumulated amortization	(2,051)	(1,644)
Amortizable intangible assets, net	3,048	3,455
Patents (estimated life 14 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	142	142
Amortizable intangible assets, accumulated amortization	(22)	(15)
Amortizable intangible assets, net	$ 120	$ 127