Condensed Consolidated Statements Of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 235,000	$ 2,244,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	913,000	1,136,000
Provision for doubtful accounts	(80,000)
Deferred taxes		327,000
Foreign currency transaction (gains) losses	57,000	(36,000)
Realized gains on available for sale securities	(4,000)
Stock compensation costs	253,000	248,000
Changes in operating assets and liabilities:
Accounts receivable	3,361,000	(2,257,000)
Inventories	(1,441,000)	(216,000)
Income tax refunds receivable	(343,000)	48,000
Other assets	(143,000)	213,000
Accounts payable	622,000	152,000
Advance customer payments	(221,000)	(48,000)
Accrued expenses	(747,000)	287,000
Net cash provided by operating activities	2,462,000	2,098,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale marketable securities	6,460,000	5,109,000
Proceeds from sales of available-for-sale marketable securities	2,304,000	1,848,000
Purchases of available-for-sale marketable securities	(13,497,000)	(9,381,000)
Additions to equipment and leasehold improvements	(612,000)	(216,000)
Additions to patents	(75,000)	(54,000)
Net cash used in investing activities	(5,420,000)	(2,694,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options		12,000
Net cash provided by financing activities		12,000
Effects of exchange rate changes on cash and cash equivalents	30,000	15,000
Net decrease in cash and cash equivalents	(2,928,000)	(569,000)
Cash and cash equivalents - beginning of period	13,791,000	8,427,000
Cash and cash equivalents - end of period	$ 10,863,000	$ 7,858,000