Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Cash flows from operating activities:
Net income (loss)	$ 15,719	$ 24,644	$ (28,168)
Adjustments to reconcile net income (loss) to net cash provided from operating activities:
Depreciation and amortization	10,067	10,988	11,029
Share-based compensation expense	4,287	3,543	3,378
Deferred income taxes	(1,676)	(1,971)	17,360
Accrued retiree benefits	381	(222)	348
Excess tax benefit from stock options exercised	(2)	(234)
Loss on investment write-down			79
Changes in current assets and liabilities:
Accounts receivable	24,877	(23,434)	(11,226)
Inventories	(20,865)	(13,866)	708
Accounts payable	427	(4,402)	10,757
Other current assets	(1,549)	2,958	(522)
Income taxes payable, including excess stock option exercise benefits	(6,462)	7,334	(514)
Customer advances	(121)	(279)	(1,590)
Deferred profit	(12,013)	9,512	888
Accrued compensation, warranty and other liabilities	(832)	4,944	235
Net cash provided from operating activities	12,238	19,515	2,762
Cash flows from investing activities:
Purchases of short-term investments	(75,128)	(52,491)	(44,562)
Sales and maturities of short-term investments	75,657	46,979	56,458
Purchases of property, plant and equipment	(1,413)	(4,579)	(2,507)
Other assets	78	314	42
Net cash (used for) provided from investing activities	(806)	(9,777)	9,431
Cash flows from financing activities:
Issuance of stock, net	1,911	3,617	709
Excess tax benefit from stock options exercised	2	234
Cash dividends paid	(5,777)	(5,679)	(5,610)
Net cash used for financing activities	(3,864)	(1,828)	(4,901)
Effect of exchange rate changes on cash and cash equivalents	(227)	(236)	761
Net increase in cash and cash equivalents	7,341	7,674	8,053
Cash and cash equivalents at beginning of year	45,921	38,247	30,194
Cash and cash equivalents at end of year	53,262	45,921	38,247
Cash paid (refunded) during the year for:
Income taxes	10,203	(2,138)	(4,201)
Inventory capitalized as capital assets	1,380	2,990	578
Dividends declared but not yet paid	$ 1,455	$ 1,434	$ 1,410