Common and Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Dec. 01, 2015	Jan. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Increase in share repurchase authorized amount	$ 300,000
Purchase of common stock (in shares)			738,593	2,811,002	2,970,461
Purchase and accruals of common stock			$ 55,000	$ 210,500
Purchase of common stock		$ 2,300	$ 57,272	210,822	$ 219,893
Remaining authorized repurchase amount				$ 580,000
Common stock, shares authorized (in shares)			150,000,000	150,000,000
Common stock, par value (in dollars per share)			$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)			5,000,000	5,000,000
Preferred stock, par value (in dollars per share)			$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)			0	0