Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 19, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					97,541
Warrants and Rights Outstanding					$ 825,000
Net income	$ 30,598,000	$ 11,328,000	$ 364,775,000	$ 24,300,000
Weighted average shares outstanding - basic (in shares)	62,139,833	61,958,183	62,110,498	61,944,392
Dilutive securities outstanding (in shares)	706,031	83,020	634,679	292,073
Weighted average shares outstanding - diluted (in shares)	62,845,864	62,041,203	62,745,177	62,236,465
Earnings per share - basic (in dollars per share)	$ 0.49	$ 0.18	$ 5.87	$ 0.39
Earnings per share - diluted (in dollars per share)	$ 0.49	$ 0.18	$ 5.81	$ 0.39
Weighted Average antidilutive securities outstanding (in shares)	13,054	25,340	23,423	80,228
Stock options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average antidilutive securities outstanding (in shares)	13,054	16,291	14,174	16,823
Restricted shares [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average antidilutive securities outstanding (in shares)	0	9,049	9,249	63,405