Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2013	Dec. 31, 2012
At lower of LIFO cost or market:
Live hogs and materials	$ 249,976	$ 258,638
Fresh pork and materials	38,749	31,495
Inventories at lower of LIFO cost or market, Gross	288,725	290,133
LIFO adjustment	(80,926)	(90,730)
Total inventories at lower of LIFO cost or market	207,799	199,403
At lower of FIFO cost or market:
Grains, oilseeds and other commodities	406,747	317,573
Sugar produced and in process	61,603	65,986
Other	71,152	73,606
Total inventories at lower of FIFO cost or market	539,502	457,165
Grain, flour and feed at lower of weighted average cost or market	95,163	100,296
Total inventories	$ 842,464	$ 756,864