Intangible Assets (Schedule Of Amortization Expense For Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 44	$ 43	$ 86	$ 86
Patents
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	26	26	51	52
Software
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	8	8	16	15
Marketing assets and customer relationships
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	3	3	6	6
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 7	$ 6	$ 13	$ 13