Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Tax Expense (Benefit) [Abstract]
Liability for gross unrecognized tax benefits	$ 3,457		$ 3,457
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	968		968
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	1,921
Accrual for interest and penalties	114		114
Decrease in gross unrecognized tax benefits resulting from prior period tax positions			$ 905
Effective income tax rate	30.70%	28.90%	31.10%	30.80%
U.S. federal statutory income tax rate			35.00%

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 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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