Defined Benefit Plans (Details) (USD $)			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 24, 2014	Dec. 25, 2013	Sep. 24, 2014 Pension Plan [Member]	Sep. 25, 2013 Pension Plan [Member]	Sep. 24, 2014 Pension Plan [Member]	Sep. 25, 2013 Pension Plan [Member]	Sep. 24, 2014 Other Defined Benefit Plans [Member]	Sep. 25, 2013 Other Defined Benefit Plans [Member]	Sep. 24, 2014 Other Defined Benefit Plans [Member]	Sep. 25, 2013 Other Defined Benefit Plans [Member]	Sep. 24, 2014 Minimum [Member] Pension Plan [Member]	Sep. 24, 2014 Maximum [Member] Pension Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost			$ 95,000	$ 100,000	$ 285,000	$ 300,000
Interest cost			775,000	745,000	2,325,000	2,233,000	31,000	28,000	93,000	84,000
Expected return on plan assets			(988,000)	(1,122,000)	(2,965,000)	(3,366,000)
Amortization of net loss			231,000	413,000	693,000	1,240,000	15,000	17,000	46,000	53,000
Settlement loss recognized							33,000	0	58,000	0
Net periodic benefit cost			113,000	136,000	338,000	407,000	79,000	45,000	197,000	137,000
Maximum contributions made to qualified pension plan and other defined benefit plans					2,500,000	2,800,000			400,000	100,000
Maximum expected additional contributions to be made to other defined benefit plans									100,000
Additional minimum pension liability	18,300,000	18,700,000
Expected additional contributions to be made to qualified pension plan											$ 5,000,000	$ 7,000,000