Benefit Plans (Details 16) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 30, 2012
Accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost
Net periodic benefit cost, beginning balance	$ (134,204)
Actuarial gain (loss), net periodic benefit cost	(26,266)
Reclassification adjustments	3,665
Net periodic benefit cost, ending balance	(156,805)
Pension Plan [Member]
Accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost
Actuarial loss, beginning balance	(107,008)
Actuarial gain (loss)	(21,979)
Reclassification adjustments actuarial loss	2,822
Actuarial loss, ending balance	(126,165)
Prior service cost (credit) beginning balance	(73)
Actuarial gain (loss), prior service cost (credit)	0
Reclassification adjustments prior service cost (credit)	17
Prior service cost (credit) ending balance	(56)
Postretirement Medical [Member]
Accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost
Actuarial loss, beginning balance	(35,823)
Actuarial gain (loss)	(4,287)
Reclassification adjustments actuarial loss	2,339
Actuarial loss, ending balance	(37,771)
Prior service cost (credit) beginning balance	8,700
Actuarial gain (loss), prior service cost (credit)	0
Reclassification adjustments prior service cost (credit)	(1,513)
Prior service cost (credit) ending balance	$ 7,187