CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Common stock $1 par value [Member]	Paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]
Beginning balance at Dec. 26, 2009	$ 257,249	$ 23,547	$ 64,847	$ 160,193	$ 8,662
Net income loss	24,644			24,644
Changes in cumulative translation adjustment	(7,270)				(7,270)
Adjustments related to postretirement benefits, net of income taxes	(1,506)				(1,506)
Changes in unrealized gains and losses on investments, net of income taxes	(83)				(83)
Cash dividends - $0.24 per share	(5,703)			(5,703)
Exercise of stock options	2,869	263	2,606
Shares issued under employee stock purchase plan	1,213	112	1,101
Shares issued for restricted stock units vested		101	(101)
Repurchase and retirement of stock	(465)	(34)	(431)
Share-based compensation expense	3,543		3,543
Tax benefit from equity awards	234		234
Ending balance at Dec. 25, 2010	274,725	23,989	71,799	179,134	(197)
Net income loss	15,719			15,719
Changes in cumulative translation adjustment	(1,076)				(1,076)
Adjustments related to postretirement benefits, net of income taxes	1,267				1,267
Changes in unrealized gains and losses on investments, net of income taxes	(6)				(6)
Cash dividends - $0.24 per share	(5,798)			(5,798)
Exercise of stock options	1,111	123	988
Shares issued under employee stock purchase plan	1,262	120	1,142
Shares issued for restricted stock units vested		139	(139)
Repurchase and retirement of stock	(462)	(41)	(421)
Share-based compensation expense	4,287		4,287
Tax benefit from equity awards	2		2
Ending balance at Dec. 31, 2011	291,031	24,330	77,658	189,055	(12)
Net income loss	(12,243)			(12,243)
Changes in cumulative translation adjustment	1,689				1,689
Adjustments related to postretirement benefits, net of income taxes	122				122
Changes in unrealized gains and losses on investments, net of income taxes	(16)				(16)
Cash dividends - $0.24 per share	(5,875)			(5,875)
Exercise of stock options	609	73	536
Shares issued under employee stock purchase plan	1,252	152	1,100
Shares issued for restricted stock units vested		108	(108)
Repurchase and retirement of stock	(291)	(31)	(260)
Share-based compensation expense	4,621		4,621
Ending balance at Dec. 29, 2012	$ 280,899	$ 24,632	$ 83,547	$ 170,937	$ 1,783