Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended	1 Months Ended
	Aug. 01, 2007	Sep. 30, 2011	Oct. 26, 2011 Dividend Declared
Stockholders Equity Note [Line Items]
Dividend declaration date			Oct. 26, 2011
Dividend per share, declared			$ 0.05
Dividend payment date			Dec. 30, 2011
Dividend record date			Dec. 15, 2011
Amount approved for repurchases under stock buyback program	$ 250,000,000
Treasury stock shares acquired		8,025
Treasury stock repurchased, value		242,000
Amount authorized to purchase the Company's outstanding common stock under the program		113,000,000
Treasury stock shares acquired from employees		130,921
Purchase price for treasury stock acquired from employees		$ 4,000,000