Preferred and Common Stock - Additional information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended		1 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Sep. 05, 2012 Maximum
Class of Stock [Line Items]
Stock repurchase program, authorized amount			$ 50
Treasury stock acquired	$ 0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0