EMPLOYEE BENEFIT PLANS - Components of Net Period Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Retirement Benefits [Abstract]
Service cost	$ 3,110	$ 2,453	$ 4,293
Interest cost	11,642	12,046	12,974
Expected return on plan assets	(14,249)	(14,164)	(16,987)
Amortization of prior service cost (credit)	(496)	(292)	(581)
Amortization of net loss (gain)	3,845	2,003	3,198
Curtailment	0	(279)	0
Settlements	0	788	0
Net periodic cost (benefit)	$ 3,852	$ 2,555	$ 2,897