SEGMENT INFORMATION - Schedule of Net Sales From External Customers by Product Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 29, 2024	Mar. 31, 2023	Mar. 29, 2024	Mar. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 792,911	$ 895,934	$ 1,591,392	$ 1,729,755
Electrical
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	590,811	680,955	1,184,471	1,319,660
Electrical | Metal Electrical Conduit and Fittings
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	147,697	128,322	286,936	239,480
Electrical | Electrical Cable & Flexible Conduit
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	114,634	129,785	230,327	253,511
Electrical | Plastic Pipe and Conduit
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	233,713	323,139	477,554	639,304
Electrical | Other Electrical products
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	94,767	99,709	189,654	187,365
Safety & Infrastructure
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	202,100	214,979	406,921	410,095
Safety & Infrastructure | Mechanical Pipe
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	88,866	98,727	173,364	177,501
Safety & Infrastructure | Other Safety & Infrastructure products
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 113,234	$ 116,252	$ 233,557	$ 232,594