Earnings per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended		15 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012
Earnings Per Share [Abstract]
Net Income	$ 11,880	$ 32,681	$ 33,283	$ 18,872
Less: Earnings allocated to participating securities	(113)	(336)	(311)	(177)
Earnings allocated to common shareholders, Basic	11,767	32,345	32,972	18,695
Weighted average common shares outstanding	39,289	39,248	39,092	39,131
Basic earnings per common share	$ 0.30	$ 0.82	$ 0.84	$ 0.48
Dilutive effect of equity awards and warrants	2	3	75	61
Earnings allocated to common shareholders, Diluted	$ 11,767	$ 32,345	$ 32,972	$ 18,695
Weighted average diluted common shares outstanding	39,291	39,251	39,167	39,192
Diluted earnings per common share	$ 0.30	$ 0.82	$ 0.84	$ 0.48
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	53	46	62	75