Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended		3 Months Ended	6 Months Ended	24 Months Ended
	May 12, 2014	May 09, 2012	Jun. 30, 2014	Jun. 30, 2014	May 09, 2014
Equity [Abstract]
Stock repurchase program, amount authorized	$ 150,000,000	$ 100,000,000
Stock repurchase program period authorized for repurchasing		2 years
Stock repurchased during period, number of shares			239,800	70,010	4,338,306
Stock repurchased during period, average price			$ 16.35	$ 15.93	$ 10.67
Stock repurchased during period, aggregate purchase price including transaction costs			3,900,000	1,100,000	46,300,000
Stock repurchase program, remaining amount				$ 146,100,000