PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Defined Benefit Plan Obligations and Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014	Dec. 28, 2014	Dec. 29, 2013
Change in plan assets:
Fair value of plan assets, beginning of period			$ 113,552
Fair value of plan assets, end of period	$ 104,189		104,189
Pension Benefits [Member]
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			190,401	$ 170,030
Interest cost	1,939	$ 2,026	3,877	4,052
Actuarial losses (gains)			(7,033)	14,864
Benefits paid			(2,981)	(6,186)
Curtailments and settlements			(13,014)	0
Projected benefit obligation, end of period	171,250	182,760	171,250	182,760
Change in plan assets:
Fair value of plan assets, beginning of period			113,552	108,496
Actual return on plan assets			3,455	2,977
Contributions by employer			3,177	3,328
Benefits paid			(2,981)	(6,186)
Curtailments and settlements			(13,014)	0
Fair value of plan assets, end of period	104,189	108,615	104,189	108,615
Funded status:
Unfunded benefit obligation, end of period	(67,061)		(67,061)		$ (76,849)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(9,363)		(9,363)		(9,373)
Long-term liability	(57,698)		(57,698)		(67,476)
Recognized liability	(67,061)		(67,061)		(76,849)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss (gain)	33,133	32,003	33,133	32,003	43,907	$ 16,957
Other Benefits [Member]
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			1,657	1,705
Interest cost	17	20	34	40
Actuarial losses (gains)			(27)	79
Benefits paid			(64)	(74)
Curtailments and settlements			0	0
Projected benefit obligation, end of period	1,600	1,750	1,600	1,750
Change in plan assets:
Fair value of plan assets, beginning of period			0	0
Actual return on plan assets			0	0
Contributions by employer			64	74
Benefits paid			(64)	(74)
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	(1,600)		(1,600)		(1,657)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(129)		(129)		(129)
Long-term liability	(1,471)		(1,471)		(1,528)
Recognized liability	(1,600)		(1,600)		(1,657)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss (gain)	$ (153)	$ (47)	$ (153)	$ (47)	$ (127)	$ (126)