Intangible assets (Detail) - USD ($) $ in Thousands	Oct. 31, 2017	Oct. 31, 2016
Intangible Assets [Line Items]
Amortizable intangible assets, net	$ 3,030	$ 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	(310)	(273)
Amortizable intangible assets, net	0	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	(2,186)	(1,644)
Amortizable intangible assets, net	2,913	3,455
Patents (estimated life 14 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	142	142
Amortizable intangible assets, accumulated amortization	(25)	(15)
Amortizable intangible assets, net	$ 117	$ 127