Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current tax expense (benefit) :
U.S. Federal	$ 6,082	$ 1,110	$ (121)
State	2,752	1,868	(455)
Foreign	7,234	6,427	5,438
Total current	16,068	9,405	4,862
Deferred tax expense (benefit) :
U.S. Federal	26,373	17,532	(10,326)
State	372	552	1,108
Foreign	186	(244)	2,140
Total deferred	26,931	17,840	(7,078)
Total provision	$ 42,999	$ 27,245	$ (2,216)