Income Tax (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Tax [Abstract]
Operating expenses not currently deductible	$ 4,992	$ 4,597
Stock options and other employee benefit plans	5,666	5,156
Capital loss carryforward	145	203
Property and equipment	531	397
Total deferred income tax assets	11,334	10,353
Intangible assets	(10,868)	(10,043)
Other	(143)	(156)
Total deferred income tax liabilities	(11,011)	(10,199)
Net deferred income tax assets (liabilities)	$ 323	$ 154