Income Taxes (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes (Textual) [Abstract]
Estimated Federal Taxable Income	$ 72,351	$ 117,801
Statutory Federal income tax rate	35.00%
Effective tax rate	37.65%	36.10%	35.60%
Unrecognized tax benefits that would impact effective tax rate	29,283
Accrued interest on unrecognized tax benefits	2,076	573	932
Total accrued interest on unrecognized tax benefits	24,797	22,721
Reduction in Unrecognized tax benefits	$ 3,945

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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- Definition

This element represents the amount of interest expense accrued as of the date of the statement of financial position for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

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- Definition

This element represents interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity.

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