Other Income (Expense) Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	$ 1,783	$ 1,082	$ 632
Investment Income [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	116	27	162
Licensing fees [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	1,211	449	230
Other [Member]
Component of Other Income, Nonoperating [Line Items]
Other income, net of expenses	$ 456	$ 606	$ 240