Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Oct. 15, 2011 Building sqft	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2010
Commitments and Contingencies [Line Items]
Rent expenses		$ 62.0	$ 58.1	$ 49.7
Number of buildings to be leased	2
Total square feet of buildings	341,000
Lease initiation date	March 1, 2015
Lease expiration period, (in years)	15 years
Extended lease term, years	19 years