Noncontrolling interests (Details) (USD $)	3 Months Ended		6 Months Ended				6 Months Ended
	Jul. 03, 2011	Jul. 04, 2010	Jul. 03, 2011	Jul. 04, 2010	Jul. 03, 2011 Common Stock [Member]	Dec. 31, 2010 Common Stock [Member]	Jul. 03, 2011 Additional Paid-in Capital [Member]	Jul. 03, 2011 Retained Earnings [Member]	Jul. 03, 2011 Accumulated Other Comprehensive Income (Loss) [Member]	Jul. 03, 2011 Treasury Stock [Member]	Jul. 03, 2011 Noncontrolling Interest [Member]
Total shareholders' equity			$ 782,695,000		$ 2,900,000	$ 2,900,000	$ 323,200,000	$ 899,200,000	$ (3,600,000)	$ (466,200,000)	$ 27,200,000
Comprehensive Income [Abstract]
Consolidated net income	17,156,000	19,633,000	33,846,000	35,735,000				32,200,000			1,700,000
Currency translation adjustment	5,100,000	(20,500,000)	22,200,000	(33,800,000)					20,900,000		1,300,000
Unamortized pension gains and prior service costs	1,900,000	1,100,000	3,000,000	2,100,000					3,000,000
Cash flow hedge [Abstract]
Net derivative gains (losses) arising during the year	(400,000)	3,500,000	(1,400,000)	5,000,000					(1,400,000)
Reclassification adjustment			0
Total comprehensive income (loss)			57,600,000					32,200,000	22,500,000		2,900,000
Dividends declared			(1,800,000)					(1,800,000)
Dividends to non-controlling interest			(500,000)								(500,000)
Employee benefit transactions			4,800,000				4,800,000
Income tax benefit arising from employee stock option plans			100,000				100,000
Stock based compensation			2,300,000				2,300,000
Purchase of common stock			(23,600,000)							(23,600,000)
Total shareholders' equity	$ 821,649,000		$ 821,649,000		$ 2,900,000	$ 2,900,000	$ 330,500,000	$ 929,600,000	$ 18,900,000	$ (489,900,000)	$ 29,600,000