Summary of status of options granted under stock option plans and changes in options outstanding (Detail)	9 Months Ended
	Jul. 31, 2016 $ / shares shares
Shares
Options Outstanding at beginning of year | shares	1,240,100
Options granted | shares	104,936
Options exercised | shares	(180,067)
Options canceled or expired | shares	(71,118)
Options outstanding at end of year | shares	1,093,851
Options exercisable at end of year | shares	634,598
Options vested and expected to vest at end of year | shares	1,087,360
Weighted Average Exercise Price
Options outstanding at beginning of year | $ / shares	$ 3.64
Options granted | $ / shares	3.36
Options exercised | $ / shares	0.27
Options canceled or expired | $ / shares	4.52
Options outstanding at end of year | $ / shares	4.11
Options exercisable at end of year | $ / shares	3.83
Options vested and expected to vest at end of year | $ / shares	$ 4.11