Short And Long-Term Debt (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Short And Long-Term Debt Instrument [Line Items]
Inventory cap on borrowing base			$ 4,500,000
Annual capital expenditure allowed			5,500,000
Interest expense	$ 211,000	$ 189,000	405,000	$ 371,000
Domestic Term-Loan [Member]
Short And Long-Term Debt Instrument [Line Items]
Loan amount	6,500,000		6,500,000
Quarterly installments			$ 250,000
Percentage of proceeds from certain asset sales required to pay down term loan			100.00%
Debt	5,750,000		$ 5,750,000		$ 6,250,000
Domestic Asset-based Revolving Credit Facility [Member]
Short And Long-Term Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 9,000,000		$ 9,000,000
Weighted average interest rate of debt instruments	5.25%		5.25%		5.11%
Debt	$ 6,394,000		$ 6,394,000		$ 4,000,000
Letters Of Credit [Member]
Short And Long-Term Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	200,000		200,000
Capital Expenditure Loan Facility [Member]
Short And Long-Term Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	2,500,000		2,500,000
Debt
Foreign Overdraft And Letter Of Credit Facility [Member]
Short And Long-Term Debt Instrument [Line Items]
Weighted average interest rate of debt instruments	4.30%		4.30%		3.87%
Debt	$ 1,241,000		$ 1,241,000		$ 1,250,000
Foreign Overdraft And Letter Of Credit Facility [Member] | Minimum [Member]
Short And Long-Term Debt Instrument [Line Items]
Interest rate of debt instruments	0.75%		0.75%
Foreign Overdraft And Letter Of Credit Facility [Member] | Maximum [Member]
Short And Long-Term Debt Instrument [Line Items]
Interest rate of debt instruments	2.50%		2.50%