Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax [Line Items]
Recognized tax expense on remeasurement of certain deferred tax assets and liabiliites		$ 1,662,000
U.S. corporate income tax		34.00%
Recognized provisional tax expense on transition tax for repatriation of foreign earnings		$ 565,000
Computation of one-time tax based on liquid asset period		3 years
Tax expense impacted by cash and other liquid assets		15.50%
Tax expense impacted by non-cash E&P		8.00%
Current:
Federal		$ 0	$ 0
State and local		18,000	8,000
Foreign		43,000	41,000
Total Current		61,000	49,000
Deferred:
Federal		1,637,000	(211,000)
State and local		42,000	267,000
Foreign		41,000	55,000
Total before change in valuation allowance		1,720,000	111,000
Change in Valuation Allowance		(1,679,000)	(325,000)
Net Deferred		41,000	(214,000)
Income tax provision (benefit)		102,000	(165,000)
Reconciliation of provision (benefit) for income taxes [Abstract]
Tax provision (benefit) at expected statutory rate		75,000	(8,000)
State taxes, net of federal benefit		81,000	(25,000)
Permanent differences		450,000	6,000
Credits		(106,000)	(123,000)
Foreign tax expense, and other		(381,000)	11,000
True-up to State NOL		0	299,000
Change in rate		1,662,000	0
Change in Valuation Allowance		(1,679,000)	(325,000)
Income tax provision (benefit)		102,000	(165,000)
Loss before income taxes from domestic operations		(65,000)	(434,000)
Profit before income taxes from foreign operations		284,000	417,000
Net deferred tax assets		173,000	214,000
Deferred tax assets [Abstract]
Inventory reserve		325,000	1,083,000
Fixed assets		0	0
Other reserves and accruals		133,000	213,000
Stock-based compensation		18,000	384,000
Undistributed foreign earnings		0	0
Other		0	0
Tax credit carry-forwards		2,284,000	1,921,000
Federal tax loss carry-forwards		2,380,000	3,428,000
State tax loss carry-forwards		657,000	627,000
Foreign tax loss carry-forwards		173,000	214,000
Total deferred income taxes		5,970,000	7,870,000
Valuation allowance		(5,627,000)	(7,305,000)
Net deferred tax assets		173,000	214,000
Deferred tax liabilities [Abstract]
Inventory reserve		0	0
Fixed assets		141,000	151,000
Other reserves and accruals		0	0
Stock-based compensation		0	0
Undistributed foreign earnings		0	144,000
Other		29,000	56,000
Total deferred income tax liabilities		170,000	$ 351,000
Research and Development Credit Carryforwards [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Tax credit carryforward amount		$ 1,515,000
Research and Development Credit Carryforwards [Member] | Minimum [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Expiration date		Dec. 31, 2020
Research and Development Credit Carryforwards [Member] | Maximum [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Expiration date		Dec. 31, 2038
Foreign Tax Credit Carryforward [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Tax credit carryforward amount		$ 727,000
Foreign Tax Credit Carryforward [Member] | Minimum [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Expiration date		Dec. 31, 2018
Foreign Tax Credit Carryforward [Member] | Maximum [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Expiration date		Dec. 31, 2020
Federal [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Net operating loss carryforwards		$ 11,333,000
Expiration date		Dec. 31, 2037
State [Member]
Reconciliation of provision (benefit) for income taxes [Abstract]
Net operating loss carryforwards		$ 16,985,000
Expiration date		Dec. 31, 2037
Scenario, Plan [Member]
Income Tax [Line Items]
U.S. corporate income tax	21.00%