Earnings per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share [Abstract]
Net Income	$ 8,902	$ 5,779
Less: Earnings allocated to participating securities	(132)	(53)
Earnings allocated to common shareholders, Basic	8,770	5,726
Weighted average common shares outstanding	39,195	39,043
Basic earnings per common share	$ 0.22	$ 0.15
Dilutive effect of equity awards and warrants	103	113
Earnings allocated to common shareholders, Diluted	$ 8,770	$ 5,726
Weighted average diluted common shares outstanding	39,298	39,156
Diluted earnings per common share	$ 0.22	$ 0.15
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	46	54

Basic earnings allocated to common shareholders

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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