Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current Federal	$ 5,652	$ 5,105	$ 2,526
Current State	3,686	2,728	2,724
Deferred Federal	12,578	14,037	6,764
Deferred State	1,535	2,759	2,077
Total United States income taxes	23,451	24,629	14,091
Current Foreign	6,488	8,967	3,947
Deferred Foreign	8,592	(3,432)	(2,122)
Total foreign income taxes	15,080	5,535	1,825
Provision for income taxes	$ 38,531	$ 30,164	$ 15,916