DERIVATIVE FINANCIAL INSTRUMENTS (Schedule of Outstanding Derivative Instruments and Cash Collateral) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 01, 2018	Dec. 25, 2016	Dec. 31, 2017
Fair values:
Cash collateral posted with brokers	$ 10,657		$ 8,021
Corn
Derivatives Coverage:
Derivatives coverage (as a percentage)	11.00%	3.10%
Period through which stated percent of needs are covered:
Maturity date	Dec. 31, 2019	Mar. 31, 2019
Soybean meal
Derivatives Coverage:
Derivatives coverage (as a percentage)	12.70%	1.70%
Period through which stated percent of needs are covered:
Maturity date	Jan. 31, 2019	Dec. 31, 2018
Commodity
Fair values:
Derivative assets, gross	$ 8,110		722
Derivative liabilities, gross	(9,807)		(3,847)
Foreign currency
Fair values:
Derivative assets, gross	483		45
Derivative liabilities, gross	$ (433)		$ (211)