Condensed Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (2,146,000)	$ 92,000
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	516,000	410,000
Provision for doubtful accounts	(16,000)	(48,000)
Deferred taxes	13,000
Foreign currency transaction losses	82,000	10,000
Realized losses on available-for-sale securities	23,000
Stock compensation costs	103,000	105,000
Changes in operating assets and liabilities:
Accounts receivable	(103,000)	1,623,000
Inventories	87,000	(1,438,000)
Income tax refunds receivable	514,000	9,000
Other assets	(376,000)	(91,000)
Accounts payable	(231,000)	970,000
Advance customer payments	109,000	(58,000)
Accrued expenses	18,000	(379,000)
Net cash provided by (used in) operating activities	(1,407,000)	1,205,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale marketable securities	765,000	2,592,000
Proceeds from sales of available-for-sale marketable securities	2,453,000	1,350,000
Purchases of available-for-sale marketable securities	(3,313,000)	(8,638,000)
Additions to equipment and leasehold improvements	(95,000)	(412,000)
Additions to patents	(19,000)	(25,000)
Net cash used in investing activities	(209,000)	(5,133,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common stock repurchases	(186,000)
Net cash used in financing activities	(186,000)
Effects of exchange rate changes on cash and cash equivalents	(65,000)	77,000
Net decrease in cash and cash equivalents	(1,867,000)	(3,851,000)
Cash and cash equivalents - beginning of period	7,340,000	13,791,000
Cash and cash equivalents - end of period	$ 5,473,000	$ 9,940,000