Summary of Status of Options Granted under Stock Option Plans and Changes in Options Outstanding (Detail) (Stock Option, USD $)	6 Months Ended
	Apr. 30, 2013
Stock Option
Shares
Outstanding at November 1, 2012	2,004,781
Options granted	176,267
Options exercised	(801,077)
Options canceled or expired	(74,603)
Options outstanding at April 30, 2013	1,305,368
Options exercisable at April 30, 2013	878,770
Options vested and expected to vest at April 30, 2013	1,283,287
Weighted average exercise price
Outstanding at November 1, 2012	$ 2.25
Options granted	$ 4.80
Options exercised	$ 2.61
Options canceled or expired	$ 4.09
Options outstanding at April 30, 2013	$ 2.27
Options exercisable at April 30, 2013	$ 1.76
Options vested and expected to vest at April 30, 2013	$ 2.25