Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,965	$ 2,921
Accumulated Amortization	(2,458)	(2,372)
Net	507	549
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,557	2,513
Accumulated Amortization	(2,305)	(2,253)
Net	252	260
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	206	206
Accumulated Amortization	(68)	(53)
Net	138	153
Marketing assets and customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	101	101
Accumulated Amortization	(27)	(21)
Net	74	80
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	101	101
Accumulated Amortization	(58)	(45)
Net	$ 43	$ 56