PENSION AND OTHER POSTRETIREMENT BENEFITS - Schedule of Defined Benefit Plan Obligations and Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018	Dec. 30, 2018	Dec. 31, 2017
Change in plan assets:
Fair value of plan assets, beginning of period			$ 102,414
Fair value of plan assets, end of period	$ 107,800		107,800
Pension Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			157,619	$ 178,247
Interest cost	1,468	$ 1,366	4,402	4,097
Actuarial losses (gains)			20,726	(9,787)
Benefits paid			(4,564)	(6,857)
Curtailments and settlements			(8,783)	0
Projected benefit obligation, end of period	169,400	165,700	169,400	165,700
Change in plan assets:
Fair value of plan assets, beginning of period			102,414	112,570
Actual return on plan assets			12,637	1,853
Contributions by employer			6,096	9,474
Benefits paid			(4,564)	(6,857)
Curtailments and settlements			(8,783)	0
Fair value of plan assets, end of period	107,800	117,040	107,800	117,040
Funded status:
Unfunded benefit obligation, end of period	(61,600)		(61,600)		$ (55,205)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(8,117)		(8,117)		(8,267)
Long-term liability	(53,483)		(53,483)		(46,938)
Recognized liability	(61,600)		(61,600)		(55,205)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss (gain)	62,431	46,241	62,431	46,241	54,343	$ 54,235
Other Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			1,462	1,603
Interest cost	13	12	39	35
Actuarial losses (gains)			130	(67)
Benefits paid			(111)	(111)
Curtailments and settlements			0	0
Projected benefit obligation, end of period	1,520	1,460	1,520	1,460
Change in plan assets:
Fair value of plan assets, beginning of period			0	0
Actual return on plan assets			0	0
Contributions by employer			111	111
Benefits paid			(111)	(111)
Curtailments and settlements			0	0
Fair value of plan assets, end of period	0	0	0	0
Funded status:
Unfunded benefit obligation, end of period	(1,520)		(1,520)		(1,462)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(111)		(111)		(149)
Long-term liability	(1,409)		(1,409)		(1,313)
Recognized liability	(1,520)		(1,520)		(1,462)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss (gain)	$ 95	$ (32)	$ 95	$ (32)	$ (34)	$ 35