PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Unrecognized Benefit Amounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Pension Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net actuarial loss (gain), beginning of year	$ 54,235	$ 46,494	$ 38,115
Amortization	(1,203)	(932)	(659)
Settlement adjustments	0	0	(2,064)
Actuarial loss (gain)	(15,635)	15,745	10,305
Asset loss (gain)	16,946	(7,072)	797
Net actuarial loss (gain), end of year	54,343	54,235	46,494
Other Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net actuarial loss (gain), beginning of year	35	(31)	(79)
Amortization	0	0	0
Settlement adjustments	3	(2)	2
Actuarial loss (gain)	(72)	68	46
Asset loss (gain)	0	0	0
Net actuarial loss (gain), end of year	$ (34)	$ 35	$ (31)