Intangible assets (Detail) - USD ($) $ in Thousands	Apr. 30, 2016	Oct. 31, 2015
Intangible Assets [Line Items]
Amortizable intangible assets, net	$ 3,924	$ 4,268
Non-amortizable intangible assets, trade marks	1,387	1,387
Non-compete agreements (estimated lives 3 - 5 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	310	310
Amortizable intangible assets, accumulated amortization	(250)	(212)
Amortizable intangible assets, net	60	98
Customer relationships (estimated lives 7 - 15 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	5,099	5,099
Amortizable intangible assets, accumulated amortization	(1,373)	(1,101)
Amortizable intangible assets, net	3,726	3,998
Backlog (estimated life 1 year)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	134	134
Amortizable intangible assets, accumulated amortization	(129)	(100)
Amortizable intangible assets, net	5	34
Patents (estimated life 14 years)
Intangible Assets [Line Items]
Amortizable intangible assets, gross	142	142
Amortizable intangible assets, accumulated amortization	(9)	(4)
Amortizable intangible assets, net	$ 133	$ 138