PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Plan Asset Allocations) (Details)	Sep. 27, 2020	Dec. 29, 2019
Defined Benefit Plan Disclosure [Line Items]
Total assets	100.00%	100.00%
Cash and cash equivalents | Union Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	2.00%	4.00%
Equity securities | Union Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	2.00%	2.00%
Equity securities | GK Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	19.00%	20.00%
Equity securities | U.K. Plans
Defined Benefit Plan Disclosure [Line Items]
Total assets	33.00%	40.00%
Fixed income securities | Union Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	2.00%	2.00%
Fixed income securities | GK Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	13.00%	12.00%
Fixed income securities | U.K. Plans
Defined Benefit Plan Disclosure [Line Items]
Total assets	20.00%	18.00%
Real estate | GK Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets	2.00%	2.00%
Real estate | U.K. Plans
Defined Benefit Plan Disclosure [Line Items]
Total assets	7.00%	0.00%