Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock, at Cost [Member]
Beginning Balance at Dec. 31, 2013	$ 648,027	$ 899	$ 689,394	$ 1,886	$ 11	$ (44,163)
Beginning Balance, shares at Dec. 31, 2013	89,900,453	89,900,453
Equity-based compensation	1,905		1,905
Unrealized gain on derivatives, net of tax expense of $4	7				7
Vesting of restricted shares		1	(1)
Vesting of restricted shares, shares		84,969
Shares withheld for tax withholdings	(134)		(134)
Shares withheld for tax withholdings, shares		(4,150)
Cash dividends declared to stockholders ($0.62 per share)	(54,345)		(36,056)	(18,289)
Repurchase of 1,750,000 shares of treasury stock, at cost	(50,708)					(50,708)
Net income	75,365			75,365
Ending Balance at Sep. 30, 2014	$ 620,117	$ 900	$ 655,108	$ 58,962	$ 18	$ (94,871)
Ending Balance, shares at Sep. 30, 2014	89,981,272	89,981,272