DERIVATIVE FINANCIAL INSTRUMENTS (Schedule of Outstanding Derivative Instruments and Cash Collateral) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014
Fair values:
Cash collateral posted with brokers	$ 9,381	$ 25,205
Corn [Member]
Derivatives Coverage:
Derivatives Coverage	7.00%	(8.20%)
Soybean meal [Member]
Derivatives Coverage:
Derivatives Coverage	4.10%	(16.10%)
Commodity [Member]
Fair values:
Derivative assets	$ 1,677	$ 8,416
Derivative liabilities	(5,436)	(22,683)
Foreign currency [Member]
Fair values:
Derivative assets	$ 0	$ 2,563