DEFINED BENEFIT RETIREMENT PLAN (Details) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 26, 2015 USD ($) item $ / £	Dec. 26, 2015 GBP (£) item	Dec. 27, 2014 USD ($) $ / £	Dec. 28, 2013 USD ($)
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
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 | $ / £	1.4919		1.5557
Change in Projected Benefit Obligation
Beginning balance	$ 692,283		$ 651,857
Interest cost	24,614		28,667
Benefits paid	(18,346)		(14,498)
Actuarial loss	(28,130)		(66,889)
Currency translation	(29,232)		(40,632)
Ending balance	697,449		692,283
Plan Assets
Fair value beginning balance	542,159		497,460
Employer contributions	16,500		18,173
Actual return on plan assets	(306)		72,820
Settlements			(14,498)
Benefits paid	(18,346)		(14,498)
Currency translation	(21,881)		(31,796)
Fair Value ending balance	518,126		542,159
Funded status
Funded status	(179,323)		(150,124)	$ (154,397)
Accumulated other comprehensive income (loss)
Balance at the beginning of the period	(55,953)		(38,808)
Actuarial loss	(53,661)		(18,980)
Currency translation gain (loss)	2,655		1,835
Balance at the end of the period	(106,959)		$ (55,953)
The estimated amount to be amortized from accumulated other comprehensive income into net periodic benefit cost in 2015	$ 1,500
Weighted average actuarial assumptions used to determine the benefit obligation
Discount rate (as a percent)	3.75%		3.65%
CPI index (as a percent)	2.15%		2.10%
RPI Inflation (as a percent)	3.25%		3.20%
Net periodic benefit expense:
Interest cost	$ 24,614		$ 28,667
Expected return on plan assets	(25,224)		(26,029)
Net periodic benefit expense	$ (610)		$ 2,638
Weighted average actuarial assumptions used to determine expense
Discount rate (as a percent)	3.65%	3.65%	4.45%
Expected return on plan assets (as a percent)	5.00%	5.00%	5.50%
RPI index (as a percent)	2.10%	2.10%	2.70%
CPI index (as a percent)	3.20%	3.20%	3.60%
Limit on employer contributions per annum	$ 14,919	£ 10,000
Administrative costs of the Plan	1,641	£ 1,100
Expected pension benefit payments
2016	18,500
2017	19,100
2018	19,700
2019	20,300
2020	20,900
2021-2025	$ 114,725
Weighted average maturity period of corporate bond portfolio	13 years	13 years