Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012	Dec. 29, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 445,422	$ 387,108
Net income	32,405	28,571
Interest expense	(5,625)	(6,925)
Assets	1,591,793		1,552,416
Rendering [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	367,174	322,312
Net income	71,679	64,578
Assets	1,090,394		1,088,775
Bakery [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	78,248	64,796
Net income	14,440	11,052
Assets	169,738		170,566
Unallocated Amount to Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net income	(48,089)	(40,134)
Interest expense	(5,625)	(6,925)
Assets	$ 331,661		$ 293,075