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CASH FLOW SUPPLEMENTARY INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017	Feb. 11, 2019
Noncash or Part Noncash Acquisitions [Line Items]
Interest	$ 39,032	$ 43,305	$ 44,528
Income taxes	43,629	$ 47,355	$ 63,791
United Galvanizing
Noncash or Part Noncash Acquisitions [Line Items]
Consideration transferred	2,000			$ 2,000
Larson Camouflage
Noncash or Part Noncash Acquisitions [Line Items]
Consideration transferred	$ 3,456