Stockholders' Equity - Schedule of Outstanding Stock Options, Excluding Performance Based Options (Detail) - $ / shares	12 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Schedule Of Stock Option Activity [Line Items]
Outstanding, end of year (shares)	14,973,651
Options Outstanding, Weighted Average Remaining Life	7 years 9 months
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 1.95	$ 4.52	$ 4.83	$ 4.49
Exercisable, end of year (shares)	5,061,984
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 3.84	$ 4.24	$ 4.72
$0.63 - $2.34
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	0.63
Range of Exercise Prices, Maximum	$ 2.34
Outstanding, end of year (shares)	11,616,667
Options Outstanding, Weighted Average Remaining Life	8 years 8 months
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 1.05
Exercisable, end of year (shares)	1,936,667
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 2.03
$2.35 - $4.60
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	2.35
Range of Exercise Prices, Maximum	$ 4.60
Outstanding, end of year (shares)	1,302,500
Options Outstanding, Weighted Average Remaining Life	4 years 3 months
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 3.09
Exercisable, end of year (shares)	1,302,500
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 3.09
$4.61 - $6.64
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	4.61
Range of Exercise Prices, Maximum	$ 6.64
Outstanding, end of year (shares)	1,408,484
Options Outstanding, Weighted Average Remaining Life	4 years 8 months
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 5.37
Exercisable, end of year (shares)	1,326,817
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 5.29
$6.65 - $8.70
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	6.65
Range of Exercise Prices, Maximum	$ 8.70
Outstanding, end of year (shares)	400,000
Options Outstanding, Weighted Average Remaining Life	6 years 10 months 24 days
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 7.42
Exercisable, end of year (shares)	250,000
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 7.77
$8.71 - $10.75
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	8.71
Range of Exercise Prices, Maximum	$ 10.75
Outstanding, end of year (shares)	195,000
Options Outstanding, Weighted Average Remaining Life	2 years 2 months
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 9.00
Exercisable, end of year (shares)	195,000
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 9.00
$10.76 - $16.36
Schedule Of Stock Option Activity [Line Items]
Range of Exercise Prices, Minimum	10.76
Range of Exercise Prices, Maximum	$ 16.36
Outstanding, end of year (shares)	51,000
Options Outstanding, Weighted Average Remaining Life	10 months 24 days
Options Outstanding, Weighted Average Exercise Price (usd per share)	$ 14.52
Exercisable, end of year (shares)	51,000
Options Exercisable, Weighted Average Exercise Price (usd per share)	$ 14.52