ACQUISITIONS - Narrative (Details) $ in Thousands									3 Months Ended	12 Months Ended
	Jan. 26, 2024 USD ($)	Aug. 31, 2023 USD ($) payment	Aug. 31, 2023 AUD ($)	Aug. 10, 2022 USD ($)	Jun. 01, 2022 USD ($)	May 10, 2022 USD ($)	May 12, 2021 USD ($)	Apr. 20, 2021 USD ($)	Mar. 30, 2024 USD ($)	Dec. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 25, 2021 USD ($)	Aug. 31, 2023 AUD ($) payment
Business Acquisition [Line Items]
Acquisitions, net of cash acquired										$ 32,676,000	$ 39,287,000	$ 312,500,000
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Goodwill										632,964,000	739,861,000	$ 708,566,000
Operating lease liabilities										182,296,000	172,326,000
Redeemable noncontrolling interests										$ 62,792,000	$ 60,865,000
Minority Interest Owner | Subsequent Event [Member]
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Consideration transferred									$ 10,518,000
HR Products
Business Acquisition [Line Items]
Acquisitions, net of cash acquired		$ 37,302,000	$ 58,044
Retention fund, withheld		$ 4,626,000											$ 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		$ 24,816,000
Property, plant, and equipment		1,379,000
Goodwill		9,177,000
Other non-current assets		3,997,000
Total fair value of assets acquired		51,001,000
Current Liabilities		4,183,000
Operating lease liabilities		2,792,000
Deferred income taxes		3,489,000
Total fair value of liabilities assumed		10,464,000
Net assets acquired		40,537,000
Other non-current assets		3,997,000
Goodwill expected to be tax deductible		0
ConcealFab
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Current assets					$ 21,133,000
Property, plant, and equipment					3,813,000
Goodwill					42,465,000
Other non-current assets					9,108,000
Total fair value of assets acquired					107,719,000
Current Liabilities					6,658,000
Long-term debt					2,038,000
Operating lease liabilities					7,812,000
Deferred income taxes					5,464,000
Other non-current liabilities					12,000
Total fair value of liabilities assumed					21,984,000
Redeemable noncontrolling interests					41,693,000
Net assets acquired					44,042,000
Other non-current assets					$ 9,108,000
Percentage acquired					51.00%
Cash paid to acquire business					$ 39,287,000
Contingent consideration liability, current					1,850,000
ConcealFab | Subsequent Event [Member]
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Percentage acquired	9.00%
Consideration transferred	$ 7,227,000
Prospera
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Current assets							$ 647,000
Property, plant, and equipment							1,063,000
Goodwill							273,453,000
Total fair value of assets acquired							310,913,000
Current Liabilities							2,690,000
Deferred income taxes							8,223,000
Total fair value of liabilities assumed							10,913,000
Net assets acquired							300,000,000
Cash paid to acquire business							300,000,000
Goodwill expected to be tax deductible							0
PivoTrac
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Goodwill								$ 10,800,000
Cash paid to acquire business								12,500,000
Consideration transferred								14,000,000
Contingent consideration liability, current								1,500,000
Goodwill expected to be tax deductible								0
Convert Italia S.p.A.
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Percentage acquired				9.00%
Consideration transferred				$ 3,046,000
Valmont West Coast Engineering
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Percentage acquired						20.00%
Consideration transferred						$ 4,292,000
Customer relationships | HR Products
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets		$ 11,632,000
Customer relationships | ConcealFab
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets					26,200,000
Customer relationships | PivoTrac
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets								$ 2,627,000
Useful life								8 years
Proprietary technology intangible asset related to Prospera | Prospera
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets							$ 32,900,000
Useful life							5 years
Trade names | ConcealFab
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets					$ 5,000,000
Trade names | Prospera
Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Intangible assets							$ 2,850,000
Useful life							7 years