Other Financial Statement Data Other Financial Statement Data (Schedule Of Accrued Expenses) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Wages and benefits	$ 1,121	$ 1,328
Warranty liability	690	713	$ 705
Other	530	244
Accrued expenses	$ 2,341	$ 2,285