Other Income (Expense) Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	$ 1,084	$ 675	$ 1,137
Interest Income [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	27	129	615
Licensing Fees [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	449	230	215
Other Nonoperating Income [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	$ 608	$ 316	$ 307