Consolidated Statements of Equity (USD $) In Thousands, unless otherwise specified		Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Total
Balance at Jan. 02, 2010		$ 218	$ 130,870		$ 18,727	$ 228,641	$ 143	$ 378,599
Comprehensive income:
Net income for the year						78,663		78,663
Change in net unrealized gain on derivatives*	[1]				92			92
Pension liability adjustments	[1]				(3,044)			(3,044)
Unrealized gain on investments	[1]				696			696
Foreign currency translation adjustments					4,770			4,770
Comprehensive income								81,177
Stock-based compensation			5,243					5,243
Withheld shares on restricted stock grants for withholding taxes				(422)				(422)
Purchase of shares of common stock		(6)	(2,247)	(23,124)				(25,377)
Stock options exercised, including tax impact		6	16,682					16,688
Cash dividends paid						(3,248)		(3,248)
Balance at Jan. 01, 2011		218	150,548	(23,546)	21,241	304,056	143	452,660
Comprehensive income:
Net income for the year						87,024		87,024
Pension liability adjustments	[1]				(6,703)			(6,703)
Unrealized gain on investments	[1]				(2,702)			(2,702)
Foreign currency translation adjustments					(3,205)			(3,205)
Comprehensive income								74,414
Stock-based compensation			5,805					5,805
Withheld shares on restricted stock grants for withholding taxes				(1,203)				(1,203)
Purchase of shares of common stock		(9)	(2,998)	(34,085)				(37,092)
Stock options exercised, including tax impact		7	21,020					21,027
Cash dividends paid						(14,508)		(14,508)
Balance at Dec. 31, 2011		216	174,375	(58,834)	8,631	376,572	143	501,103
Comprehensive income:
Net income for the year						75,332		75,332
Pension liability adjustments	[1]				(7,301)			(7,301)
Unrealized gain on investments	[1]				1,225			1,225
Foreign currency translation adjustments					13,993			13,993
Comprehensive income								83,249
Stock-based compensation			7,348					7,348
Withheld shares on restricted stock grants for withholding taxes				(1,662)				(1,662)
Stock options exercised, including tax impact		4	14,080					14,084
Cash dividends paid						(16,564)		(16,564)
Balance at Dec. 29, 2012		$ 220	$ 195,803	$ (60,496)	$ 16,548	$ 435,340	$ 143	$ 587,558

[1] Including related tax impact (see Note 15).