SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Oct. 03, 2020	Sep. 28, 2019
Disaggregation of Revenue [Line Items]
Total net sales	$ 1,227,253	$ 1,285,043	$ 3,426,000	$ 3,645,332
Windows
Disaggregation of Revenue [Line Items]
Total net sales	501,314	504,338	1,378,039	1,434,579
Windows | Vinyl windows
Disaggregation of Revenue [Line Items]
Total net sales	465,472	473,202	1,283,337	1,334,747
Windows | Aluminum windows
Disaggregation of Revenue [Line Items]
Total net sales	22,056	18,404	61,338	56,490
Windows | Aluminum windows | Revision of Prior Period, Reclassification, Adjustment [Member]
Disaggregation of Revenue [Line Items]
Total net sales		6,500		16,800
Windows | Other products & services
Disaggregation of Revenue [Line Items]
Total net sales	13,786	12,732	33,364	43,342
Windows | Other products & services | Revision of Prior Period, Reclassification, Adjustment [Member]
Disaggregation of Revenue [Line Items]
Total net sales		1,400		3,800
Windows | Reclassification to aluminum windows | Revision of Prior Period, Reclassification, Adjustment [Member]
Disaggregation of Revenue [Line Items]
Total net sales		(6,500)		(16,800)
Windows | Reclassification to other | Revision of Prior Period, Reclassification, Adjustment [Member]
Disaggregation of Revenue [Line Items]
Total net sales		(1,400)		(3,800)
Siding
Disaggregation of Revenue [Line Items]
Total net sales	321,898	315,799	848,190	840,601
Siding | Other products & services
Disaggregation of Revenue [Line Items]
Total net sales	58,388	41,271	156,509	123,512
Siding | Vinyl siding
Disaggregation of Revenue [Line Items]
Total net sales	146,585	148,912	387,559	400,220
Siding | Metal
Disaggregation of Revenue [Line Items]
Total net sales	75,477	75,933	192,567	199,265
Siding | Injection molded
Disaggregation of Revenue [Line Items]
Total net sales	20,460	17,429	49,556	47,163
Siding | Stone
Disaggregation of Revenue [Line Items]
Total net sales	20,988	32,254	61,999	70,441
Commercial
Disaggregation of Revenue [Line Items]
Total net sales	404,041	464,906	1,199,771	1,370,152
Commercial | Metal building products
Disaggregation of Revenue [Line Items]
Total net sales	281,339	320,028	842,863	914,623
Commercial | Insulated metal panels
Disaggregation of Revenue [Line Items]
Total net sales	89,088	109,322	260,410	332,403
Commercial | Metal coil coating
Disaggregation of Revenue [Line Items]
Total net sales	$ 33,614	$ 35,556	$ 96,498	$ 123,126