Earnings Per Share (Details) (USD $) In Thousands, except Share data	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Basic and Diluted Earnings Per Share
Net earnings available to common stockholders, basic and diluted	$ 11,886	$ 13,222	$ 22,171	$ 23,292	$ 42,330
Average outstanding shares - basic	71,915,073	71,913,102	71,915,073	67,363,476
Add: dilutive stock options		1,792		901
Average outstanding shares - diluted	71,915,073	71,914,894	71,915,073	67,364,377
Basic earnings per share	$ 0.17	$ 0.19	$ 0.31	$ 0.35
Diluted earnings per share	$ 0.17	$ 0.19	$ 0.31	$ 0.35
Earnings Per Share (Textuals) [Abstract]
Exclusion of Diluted average outstanding shares from calculation			1,641,528	2,285,661

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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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=6510752

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+ Details

- Definition

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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+ Details

- Definition

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.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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+ Details