Income Taxes (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Income Taxes [Line Items]
Income tax provision (benefit)	$ 10,115,000	$ 3,651,000	$ 17,381,000	$ 5,069,000
Effective income tax rate	38.00%	31.00%	19.00%	30.00%
Statutory income tax rate			35.00%	35.00%
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	12,300,000		12,300,000
Unrecognized tax benefits that will be recognized within next twelve months	4,900,000		4,900,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense			300,000		200,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 3,400,000		$ 3,400,000		$ 3,000,000

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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-Publisher FASB

-Name Accounting Standards Codification

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

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The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

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-Name FASB Interpretation (FIN)

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- Definition

This element represents the total of accruals as of the date of the statement of financial position for interest 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 and the amount of statutory penalties for a tax position claimed or expected to be claimed by the entity, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

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This element represents the total of 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 and the amount of statutory penalties in the period in which the entity claims or expects to claim a tax position, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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