Income Taxes Schedule of Components of Income Tax Expense (Benefit) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Disclosure [Abstract]
Federal									$ 5,662	$ 3,547	$ 7,846
State									1,001	595	689
Foreign									1,491	740	238
Total current expense:									8,154	4,882	8,773
Federal									1,121	30	1,264
State									74	(545)	227
Foreign									482	(39)	300
Total deferred expense (benefit):									1,677	(554)	1,791
Total	$ 806	$ 2,120	$ 3,746	$ 3,159	$ 921	$ (1,539)	$ 3,124	$ 1,822	$ 9,831	$ 4,328	$ 10,564