Summary of Stock Option Shares Activity for the 2008 Plan (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jan. 31, 2013
Number of Shares
Outstanding at beginning of period	2,473,250
Granted	423,100
Exercised	(37,903)
Cancelled/Expired	(2,500)
Outstanding at end of period	2,855,947
Vested or expected to vest at end of period	2,765,986
Exercisable at end of period	1,877,560
Weighted Average Exercise Price Per Share
Outstanding at beginning of period	$ 14.57
Granted	$ 21.06
Exercised	$ 13.38
Cancelled/Expired	$ 20.99
Outstanding at end of period	$ 15.54
Vested or expected to vest at end of period	$ 15.44
Exercisable at end of period	$ 14.07
Weighted Average Remaining Contractual Life
Outstanding at end of period	7 years 4 months 24 days
Vested or expected to vest at end of period	7 years 4 months 24 days
Exercisable at end of period	6 years 6 months
Aggregate Intrinsic Value
Outstanding at end of period	$ 14,813
Vested or expected to vest at end of period	14,618
Exercisable at end of period	$ 12,380