DEFINED BENEFIT RETIREMENT PLAN (Details) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 25, 2021 USD ($)	Dec. 26, 2020 USD ($) item $ / £	Dec. 26, 2020 GBP (£) item	Dec. 28, 2019 USD ($) $ / £	Dec. 29, 2018 USD ($)	Dec. 29, 2018 GBP (£)
Defined Benefit Plan Disclosure [Line Items]
Pension retirement benefits to qualified employees as percent of final salary per year of service		1.67%	1.67%
Eligibility age		65 years	65 years
Active members of defined benefit retirement income plan | item		0	0
Foreign currency exchange rate used to translate the net pension liability | $ / £		1.308		1.356
Projected Benefit Obligation
Beginning balance	$ 860,173	$ 744,403		$ 647,440
Interest cost		12,954		16,923
Prior service costs - GMP equalization		949	£ 711			£ 9,500
Benefits paid		(18,212)		(20,769)
Actuarial (gain) loss		87,855		79,485
Currency translation		32,224		21,324
Ending balance		860,173		744,403	$ 647,440
Plan Assets
Fair value beginning balance	741,650	604,396		503,536
Employer contributions		35,399		18,461
Actual return on plan assets		89,988		86,081
Benefits paid		(18,212)		(20,769)
Currency translation		30,079		17,087
Fair value ending balance		741,650		604,396	503,536
Funded status
Funded status		(118,523)		(140,007)	(143,904)
Accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ (165,258)	(143,726)		(130,188)
Actuarial gain (loss)		(16,731)		(10,839)
Currency translation gain (loss)		(3,987)		(2,699)
Prior service costs - GMP equalization		(814)
Balance at the end of the period		$ (165,258)		$ (143,726)	$ (130,188)
Weighted average actuarial assumptions used to determine the benefit obligation
Discount rate		1.40%		2.05%
CPI inflation		2.00%		2.15%
RPI inflation		2.90%		3.05%
Net Periodic Benefit Cost:
Interest cost		$ 12,954		$ 16,923
Expected return on plan assets		(23,215)		(20,000)
Amortization of prior service cost		513		513
Amortization of actuarial loss		2,437		2,051
Net periodic benefit expense (benefit)		$ (7,311)		$ (513)
Weighted average actuarial assumptions used to determine expense
Discount rate		2.05%	2.05%	2.90%
Expected return on plan assets		4.18%	4.18%	4.25%
CPI Inflation		2.15%	2.15%	2.20%
RPI Inflation		3.05%	3.05%	3.30%
Limit on employer contributions per annum		$ 17,765	£ 13,100
Administrative costs of the Plan		1,763	£ 1,300
Expected pension benefit payments
2021		19,935
2022		20,477
2023		21,155
2024		21,698
2025		22,376
Years 2026 - 2030		$ 122,727
Weighted average maturity period of corporate bond portfolio		13 years	13 years
Forecast
Weighted average actuarial assumptions used to determine expense
Expected return on plan assets	3.96%