Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Equipment, leaseholds and intangible amortization, net	$ 200	$ 202
Operating lease liabilities	755
Inventory allowances	610	573
Accrued expenses	110	250
Warranty accrual	173	170
Deferred revenue	429	267
Federal and state tax credits	4,001	4,021
Federal and state net operating loss carry forwards	555	1,508
Share-based compensation	369	314
Other, net	114	122
Subtotal	7,316	7,427
Valuation allowance	(1,679)	(1,557)
Total deferred tax assets	5,637	5,870
Liabilities
Equipment, leaseholds and intangible amortization, net	287	448
Right-of-use assets (operating leases)	340
Inventory allowances	0	0
Other, net	18	0
Subtotal	645	448
Total deferred tax liabilities	$ 645	$ 448