SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2021	Apr. 04, 2020
Disaggregation of Revenue [Line Items]
Total net sales	$ 1,267,032	$ 1,113,811
Windows
Disaggregation of Revenue [Line Items]
Total net sales	527,263	448,450
Windows | Vinyl windows
Disaggregation of Revenue [Line Items]
Total net sales	497,017	419,022
Windows | Aluminum windows
Disaggregation of Revenue [Line Items]
Total net sales	20,280	19,476
Windows | Other products & services
Disaggregation of Revenue [Line Items]
Total net sales	9,966	9,952
Siding
Disaggregation of Revenue [Line Items]
Total net sales	316,391	241,043
Siding | Other products & services
Disaggregation of Revenue [Line Items]
Total net sales	57,629	46,780
Siding | Vinyl siding
Disaggregation of Revenue [Line Items]
Total net sales	150,229	109,548
Siding | Metal
Disaggregation of Revenue [Line Items]
Total net sales	71,093	52,666
Siding | Injection molded
Disaggregation of Revenue [Line Items]
Total net sales	17,609	13,239
Siding | Stone
Disaggregation of Revenue [Line Items]
Total net sales	19,831	18,810
Commercial
Disaggregation of Revenue [Line Items]
Total net sales	423,378	424,318
Commercial | Metal building products
Disaggregation of Revenue [Line Items]
Total net sales	299,938	292,436
Commercial | Insulated metal panels
Disaggregation of Revenue [Line Items]
Total net sales	85,603	99,229
Commercial | Metal coil coating
Disaggregation of Revenue [Line Items]
Total net sales	$ 37,837	$ 32,653