Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 21,048	$ 30,598	$ 71,487	$ 364,775
Weighted average shares outstanding - basic	62,309,270	62,139,833	62,280,542	62,110,498
Dilutive securities outstanding (in shares)	1,151,748	706,031	990,518	634,679
Weighted average shares outstanding - diluted	63,461,018	62,845,864	63,271,060	62,745,177
Earnings per share - basic	$ 0.34	$ 0.49	$ 1.15	$ 5.87
Earnings per share - diluted	$ 0.33	$ 0.49	$ 1.13	$ 5.81
Weighted Average antidilutive securities outstanding (in shares)	359	13,054	7,512	23,423
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	2,874,594		2,874,594		2,749,044
Class of Warrant or Right, Exercise Price of Warrants or Rights	13.26		13.26		13.86
Stock options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average antidilutive securities outstanding (in shares)	359	13,054	6,445	14,174
Restricted shares [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average antidilutive securities outstanding (in shares)	0	0	1,067	9,249