Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Cash Used in Operating Activities:
Net Income	$ 1,538	$ 1,265
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation	1,348	1,318
Amortization	184	131
Amortization of deferred gain	(130)	(130)
Provision for bad debts	(27)	4
Provision for accrued warranty costs	174	(143)
Warranty costs paid	(135)	(76)
Stock-based compensation and directors' fees	587	473
Unrealized gain on short-term investments	(7)	(24)
Unrealized (gain) loss on foreign exchange contracts	(182)	429
Unrealized foreign currency transaction gain	(105)	(152)
Changes in operating assets and liabilities:
Accounts receivable	(2,972)	(160)
Inventories	(3,814)	(6,306)
Other assets	965	(619)
Accounts payable	466	685
Other liabilities	(5,303)	(5,381)
Net Cash Used in Operating Activities	(7,413)	(8,686)
Cash (Used in) Provided by Investing Activities:
Purchases of short-term investments	(8,185)	(996)
Sales of short-term investments	7,990	2,731
Additions to property, plant and equipment	(831)	(807)
Additions to trademarks and patents	(47)	(30)
Net Cash (Used in) Provided by Investing Activities	(1,073)	898
Cash Used in Financing Activities:
Excess tax benefit from stock-based awards	353
Borrowing on long-term debt		4,500
Repayment of long-term debt	(3,000)	(4,500)
Proceeds from sale of Class A common stock, net	232	29
Purchase of treasury stock	(612)	(836)
Net Cash Used in Financing Activities	(3,027)	(807)
Effect of exchange rate changes on cash and cash equivalents	339	77
Decrease in Cash and Cash Equivalents	(11,174)	(8,518)
Cash and cash equivalents at beginning of period	25,991	16,650
Cash and Cash Equivalents at End of Period	14,817	8,132
SUPPLEMENTAL INFORMATION
Income taxes paid, net	466	175
Interest paid	$ 144	$ 218