Stockholders' Equity - Additional Information (Detail) - USD ($)			12 Months Ended
	Dec. 14, 2015	May. 24, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2012
Class of Stock [Line Items]
Preferred stock, shares issued			0	0
Preferred stock authorized			5,000,000	5,000,000
Authorized stock repurchase value			$ 300,000,000			$ 25,000,000
Common stock repurchased and retired, per shares value	$ 4.49
Common stock repurchased and retired, aggregate value	$ 49,900,000
Common stock repurchase program, authorized amount remaining			$ 45,700,000
Preferred stock, shares outstanding			0	0
Open Market Transaction [Member]
Class of Stock [Line Items]
Common stock repurchased and retired, shares			3,400,000	13,900,000	6,300,000
Common stock repurchased and retired, per shares value			$ 6.70	$ 6.70	$ 6.48
Common stock repurchased and retired, aggregate value			$ 23,000,000	$ 93,100,000	$ 40,600,000
Dutch Auction Tender Offer [Member]
Class of Stock [Line Items]
Common stock repurchased and retired, shares		12,000,000
Common stock repurchased and retired, per shares value		$ 6.25
Common stock repurchased and retired, aggregate value		$ 76,000,000
Privately Negotiated Transactions [Member]
Class of Stock [Line Items]
Common stock repurchased and retired, shares	11,100,000
Additional Paid-in Capital [Member] | Dutch Auction Tender Offer [Member]
Class of Stock [Line Items]
Common stock repurchased and retired, aggregate value		$ 1,000,000