DEFINED BENEFIT RETIREMENT PLAN (Details 2) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 29, 2018 GBP (£)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Limit on employer contributions per annum	£ 10,000	$ 12,690
Administrative costs of the Plan	£ 1,100	1,396
Plan assets at fair value		61,546	$ 18,451
Plan assets at NAV		441,990	575,298
Total plan assets		503,536	593,749	$ 486,667
Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		$ 61,546	18,451
Common stock mutual funds and diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage		50.00%
Temporary cash investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		$ 61,040	17,915
Temporary cash investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		61,040	17,915
Index linked gilts
Defined Benefit Plan Disclosure [Line Items]
Plan assets at NAV		122,711	158,011
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Plan assets at NAV		80,454	88,905
Corporate stock
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		506	536
Plan assets at NAV		183,750	212,505
Corporate stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value		506	536
Diversified growth funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets at NAV		$ 55,075	$ 115,877