ACQUISITIONS - Narrative (Details) $ in Thousands, $ in Thousands			3 Months Ended	9 Months Ended
	Aug. 31, 2023 USD ($) payment	Aug. 31, 2023 AUD ($)	Mar. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 28, 2024 USD ($)	Dec. 30, 2023 USD ($)	Aug. 31, 2023 AUD ($) payment
Business Acquisition [Line Items]
Acquisitions, net of cash acquired				$ 31,839
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Goodwill					$ 636,425	$ 632,964
HR Products
Business Acquisition [Line Items]
Acquisitions, net of cash acquired	$ 37,302	$ 58,044
Retention fund, withheld	$ 4,626						$ 7,200
Number of equal payments of retention fund | payment	2						2
Payment due of first installment of retention fund, from the date of acquisition	12 months	12 months
Payment due of second installment of retention fund, from the date of acquisition	24 months	24 months
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Current assets	$ 24,153
Property, plant, and equipment	1,397
Goodwill	9,508
Customer relationships	11,503
Other non-current assets	3,997
Total fair value of assets acquired	50,558
Current liabilities	4,183
Deferred income taxes	3,046
Operating lease liabilities	2,792
Total fair value of liabilities assumed	10,021
Net assets acquired	$ 40,537
ConcealFab
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Percentage acquired			9.00%
Consideration transferred			$ 7,227
Valmont Substations, LLC
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Consideration transferred			$ 10,518
Customer relationships
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Useful life	13 years	13 years