Stock-based compensation and equity transactions - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining life of options outstanding			5 years 14 days
Weighted average remaining contractual life of options exercisable			4 years 9 months
Weighted average life of options vested and expected to vest			5 years 18 days
Aggregate intrinsic value of options outstanding	$ 3,000,000		$ 3,000,000
Aggregate intrinsic value of options exercisable	2,800,000		2,800,000
Aggregate intrinsic value of options vested and expected to vest	3,000,000		3,000,000
Non-vested stock-based arrangements yet to be recognized	495,000		495,000
Stock based arrangements yet to be recognized, weighted average period expected to be recognized			4 years 6 months 18 days
Weighted average fair value of stock options under Black-Scholes pricing model			$ 1.99	$ 1.12
Proceeds from exercise of stock options			462,000	2,094,000
Non-employee director annual grant	30,000		30,000
Options granted for each non-employee director			7,860
Value of stock option issued			15,000
Fair value of stock option	$ 1.91		$ 1.91
Stock based compensation expense	224,000	74,000	271,000	107,000
Incentive stock options expiration date			5 years
Incentive stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive stock options			205,323
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock for exercise of stock option			167,768
Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense			30,000	25,000
Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense			$ 241,000	$ 82,000