Pension Benefits (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 283,000	$ 267,000	$ 565,000	$ 535,000
Interest cost	917,000	869,000	1,833,000	1,748,000
Expected return on plan assets	(1,000)	25,000	(1,000)	51,000
Amortization of actuarial loss	386,000	386,000	771,000	775,000
Amortization of prior service costs	3,000	0	6,000	1,000
Net periodic pension cost	1,588,000	1,547,000	3,174,000	3,110,000
Estimated employer contributions			5,400,000
Pension contributions			$ 2,400,000