Common and Preferred Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Dec. 01, 2015	Jan. 31, 2016	Jan. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Subsequent Event [Line Items]
Increase in share repurchase authorized amount	$ 300,000
Purchase of common stock (in shares)				2,811,002	2,970,461	2,916,280
Purchase and accruals of common stock				$ 210,500	$ 222,500
Purchase of common stock			$ 0	$ 210,822	219,893	$ 167,503
Remaining authorized repurchase amount					$ 635,000
Common stock, shares authorized				150,000,000	150,000,000
Common stock, par value				$ 0.01	$ 0.01
Preferred stock, shares authorized				5,000,000	5,000,000
Preferred stock, par value				$ 0.01	$ 0.01
Preferred stock, shares issued				0	0
Subsequent Event
Subsequent Event [Line Items]
Purchase of common stock		$ 2,300