Common and Preferred Stock - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended			1 Months Ended
	Nov. 08, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Apr. 30, 2013 April Settlement	Apr. 30, 2014 Subsequent Event April Settlement
Stockholders Equity Note [Line Items]
Increase in share repurchase authorized amount	$ 300,000,000
Purchase of common stock (in shares)		551,148	700,000.0
Repurchase of common stock, including subsequent settlements		40,100,000	35,700,000
Purchase of common stock		37,537,000	33,115,000		2,600,000	2,600,000
Remaining authorized repurchase amount		$ 327,800,000
Common stock, authorized (in shares)		150,000,000		150,000,000
Common stock, par value (in dollars per share)		$ 0.01		$ 0.01
Preferred stock, authorized (in shares)		5,000,000		5,000,000
Preferred stock, par value (in dollars per share)		$ 0.01		$ 0.01
Preferred stock, issued (in shares)		0		0