Income Taxes (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Asset	Dec. 31, 2010	Dec. 31, 2009
Income Taxes (Textual)
Number of definite-lived deferred tax assets	3
State net operating loss carryforwards	$ 36,912	$ 26,663
Valuation allowance on state net operating loss carryforwards	29,757	20,721
Income tax receivables	3,000	39,529
Interest and penalties recognized as income tax expense	492	1,525	472
Balance of accrued interest and penalties included in liability for unrecognized income tax benefits	2,602	4,496	3,112
Unrecognized income tax benefits that would affect the effective tax rate if recognized	9,205	12,038	12,181
Number of months after reporting period that no single tax position is anticipated that would generate a significant increase or decrease in the liability for unrecognized tax benefits	12 months
Deferred income taxes on undistributed earnings	61,000
Amount of deferred income taxes to be recognized on undistributed earnings of foreign subsidiaries	$ 21,400