Treasury Stock - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended		102 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Dec. 31, 2013
Equity [Abstract]
Common stock amount authorized under repurchase program, value (up to)					$ 150,000,000.0
Repurchase of common stock (in shares)	540,000	1,010,000	96,277	6,997,849
Average stock price of shares repurchased (in dollars per share)		$ 9.41	$ 17.66	$ 9.26
Payments for treasury stock		$ 9,533,000	$ 1,704,000	$ 64,800,000
Remaining authorized repurchase amount	$ 85,200,000	$ 85,200,000		$ 85,200,000