Retirement Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011
Domestic Pension Plans [Member]
Net pension expense/(income)
Service cost	$ 683	$ 687	$ 1,367	$ 1,374
Interest cost	2,987	3,078	5,978	6,156
Expected return on plan assets	(5,376)	(5,916)	(10,753)	(11,832)
Amortization of prior service cost	151	153	302	306
Amortization of loss	1,517	1,050	3,037	2,100
Additional cost due to retirement	282		282
Expense/(income), net	244	(948)	213	(1,896)
Foreign Pension Plans [Member]
Net pension expense/(income)
Service cost	31	35	62	70
Interest cost	143	152	285	301
Expected return on plan assets	(111)	(146)	(220)	(289)
Amortization of loss	74	70	148	139
Expense/(income), net	$ 137	$ 111	$ 275	$ 221