Employee Benefits (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 29, 2012 plan	Jun. 30, 2012	Oct. 01, 2011	Sep. 29, 2012 plan	Oct. 01, 2011
Employee Benefits
Number of defined benefit plans	2			2
Components of net periodic benefit cost:
Service cost	$ 2,221,000		$ 1,840,000	$ 6,657,000	$ 5,572,000
Interest cost	2,220,000		2,243,000	6,655,000	6,786,000
Expected return on plan assets	(1,608,000)		(1,616,000)	(4,817,000)	(4,935,000)
Amortization and other	1,550,000		1,012,000	4,647,000	3,055,000
Settlement		1,796,000		1,796,000
Net periodic benefit cost	$ 4,383,000		$ 3,479,000	$ 14,938,000	$ 10,478,000