Condensed Consolidated Statements Of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (3,346,000)	$ 235,000
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	898,000	913,000
Provision for doubtful accounts	(27,000)	(80,000)
Deferred taxes	31,000
Foreign currency transaction losses	53,000	57,000
Realized (gains) losses on available-for-sale securities	21,000	(4,000)
Stock compensation costs	233,000	253,000
Changes in operating assets and liabilities:
Accounts receivable	(1,774,000)	3,361,000
Inventories	337,000	(1,441,000)
Income tax refunds receivable	514,000	(343,000)
Other assets	(360,000)	(143,000)
Accounts payable	1,179,000	622,000
Advance customer payments	(227,000)	(221,000)
Accrued expenses	(133,000)	(747,000)
Net cash provided by (used in) operating activities	(2,601,000)	2,462,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale marketable securities	2,298,000	6,460,000
Proceeds from sales of available-for-sale marketable securities	3,522,000	2,304,000
Purchases of available-for-sale marketable securities	(4,647,000)	(13,497,000)
Additions to equipment and leasehold improvements	(458,000)	(612,000)
Additions to patents	(25,000)	(75,000)
Net cash provided by (used in) investing activities	690,000	(5,420,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common stock repurchases	(700,000)
Net cash used in financing activities	(700,000)
Effects of exchange rate changes on cash and cash equivalents	(107,000)	30,000
Net decrease in cash and cash equivalents	(2,718,000)	(2,928,000)
Cash and cash equivalents - beginning of period	7,340,000	13,791,000
Cash and cash equivalents - end of period	$ 4,622,000	$ 10,863,000