Defined Benefit Plans (Details) (USD $)			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 26, 2013	Dec. 26, 2012	Jun. 26, 2013 Pension Plan [Member]	Jun. 27, 2012 Pension Plan [Member]	Jun. 26, 2013 Pension Plan [Member]	Jun. 27, 2012 Pension Plan [Member]	Jun. 26, 2013 Other Defined Benefit Plans [Member]	Jun. 27, 2012 Other Defined Benefit Plans [Member]	Jun. 26, 2013 Other Defined Benefit Plans [Member]	Jun. 27, 2012 Other Defined Benefit Plans [Member]
Components of net periodic benefit cost [Abstract]
Service cost			$ 100,000	$ 106,000	$ 200,000	$ 190,000
Interest cost			734,000	811,000	1,488,000	1,600,000	28,000	29,000	56,000	58,000
Expected return on plan assets			(1,120,000)	(1,006,000)	(2,244,000)	(2,018,000)
Amortization of net loss			408,000	453,000	827,000	881,000	18,000	13,000	36,000	26,000
Net periodic benefit cost			122,000	364,000	271,000	653,000	46,000	42,000	92,000	84,000
Contributions made to qualified pension plan and other defined benefit plans					2,800,000	800,000			100,000	100,000
Expected additional contributions to be made to qualified pension plan and other defined benefit plans							100,000		100,000
Reclassification from accumulated other comprehensive income current period, net of tax					500,000
Additional minimum pension liability	$ 24,500,000	$ 25,000,000