SEGMENT INFORMATION - Net Income, Assets and Certain Other Items of Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 549,460	$ 566,186	$ 613,218	$ 608,218	$ 531,211	$ 575,139	$ 604,879	$ 551,832	$ 2,337,082	$ 2,263,061	$ 1,635,653
Cost of goods sold									1,914,211	1,847,195	1,356,738
Operating income									154,442	178,415	121,900
Total assets	1,470,993				1,231,231				1,470,993	1,231,231
Capital expenditures									27,661	34,486	22,497
Depreciation and amortization									62,795	55,052	33,541
Manufacturing
Segment Reporting Information [Line Items]
Net sales									1,642,263	1,745,467	1,337,785
Distribution
Segment Reporting Information [Line Items]
Net sales									694,819	517,594	297,868
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales									35,563	37,222	33,248
Intersegment Eliminations | Manufacturing
Segment Reporting Information [Line Items]
Net sales									31,223	33,581	30,669
Intersegment Eliminations | Distribution
Segment Reporting Information [Line Items]
Net sales									4,340	3,641	2,579
Operating Segments
Segment Reporting Information [Line Items]
Net sales									2,372,645	2,300,283	1,668,901
Operating income									213,866	246,737	170,493
Total assets	1,294,922				1,189,056				1,294,922	1,189,056
Capital expenditures									27,264	33,004	21,513
Depreciation and amortization									59,570	52,360	31,002
Operating Segments | Manufacturing
Segment Reporting Information [Line Items]
Net sales									1,673,486	1,779,048	1,368,454
Operating income									174,913	215,246	151,635
Total assets	990,692				948,557				990,692	948,557
Capital expenditures									25,291	31,152	21,204
Depreciation and amortization									52,036	44,747	27,481
Operating Segments | Distribution
Segment Reporting Information [Line Items]
Net sales									699,159	521,235	300,447
Operating income									38,953	31,491	18,858
Total assets	$ 304,230				$ 240,499				304,230	240,499
Capital expenditures									1,973	1,852	309
Depreciation and amortization									$ 7,534	$ 7,613	$ 3,521