SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Segment Reporting Information [Line Items]
Net sales	$ 838,171	$ 772,752	$ 1,471,195	$ 1,326,751
Segment operating profit	44,188	36,723	62,051	49,350
Intersegment net sales
Segment Reporting Information [Line Items]
Net sales	42,156	35,005	72,687	64,248
Corporate
Segment Reporting Information [Line Items]
Net sales	0	0	0	0
Segment operating profit	(1,472)	(568)	(1,693)	(3,194)
North | Operating Segments
Segment Reporting Information [Line Items]
Net sales	281,333	253,481	460,832	410,116
Segment operating profit	16,394	10,701	19,105	11,925
North | Intersegment net sales
Segment Reporting Information [Line Items]
Net sales	14,510	10,208	24,319	19,750
South | Operating Segments
Segment Reporting Information [Line Items]
Net sales	185,497	172,464	349,692	315,824
Segment operating profit	7,997	6,730	13,999	13,003
South | Intersegment net sales
Segment Reporting Information [Line Items]
Net sales	7,604	6,096	14,803	10,911
Western | Operating Segments
Segment Reporting Information [Line Items]
Net sales	309,511	295,263	567,090	520,663
Segment operating profit	18,272	17,643	28,790	26,488
Western | Intersegment net sales
Segment Reporting Information [Line Items]
Net sales	15,476	13,403	25,102	24,445
All Other | Operating Segments
Segment Reporting Information [Line Items]
Net sales	61,830	51,544	93,581	80,148
Segment operating profit	2,997	2,217	1,850	1,128
All Other | Intersegment net sales
Segment Reporting Information [Line Items]
Net sales	$ 4,566	$ 5,298	$ 8,463	$ 9,142