ACQUISITIONS - Schedule of Assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 01, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Apr. 01, 2023
Business Combination [Line Items]
Goodwill		$ 1,374,664	$ 1,161,085	$ 1,070,310
Goodwill		(3,573)	464
Saela Holdings, LLC
Business Combination [Line Items]
Cash	$ 1,522
Cash	16
Accounts receivable	805
Accounts receivable	(27)
Materials and supplies	573
Materials and supplies	0
Other current assets	414
Other current assets	0
Equipment and property	4,657
Equipment and property	9
Goodwill	129,261
Goodwill	(3,698)
Operating lease right-of-use assets	991
Operating lease right-of-use assets	0
Accounts payable	1,984
Accounts payable	23
Accrued compensation and related liabilities	1,064
Accrued compensation and related liabilities	115
Other current liabilities	557
Operating lease liabilities	168
Operating lease liabilities	991
Operating lease liabilities	0
Assets acquired and liabilities assumed	207,227
Assets acquired and liabilities assumed	94
Saela Holdings, LLC | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets	17,300
Trademarks & tradenames	0
Saela Holdings, LLC | Customer contracts
Business Combination [Line Items]
Customer contracts	56,300
Customer contracts	4,100
Acquisitions 2025
Business Combination [Line Items]
Cash		633
Accounts receivable		2,312
Materials and supplies		976
Other current assets		498
Equipment and property		6,865
Goodwill		74,875
Current liabilities		(859)
Unearned revenue		(2,907)
Other assets and liabilities, net		(5,317)
Assets acquired and liabilities assumed		130,100
Acquisitions 2025 | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets		1,786
Acquisitions 2025 | Other intangible assets
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets		1,716
Acquisitions 2025 | Customer contracts
Business Combination [Line Items]
Customer contracts		$ 49,522
2024 Acquisitions
Business Combination [Line Items]
Cash			1,671
Accounts receivable			4,954
Materials and supplies			1,053
Other current assets			446
Equipment and property			8,251
Goodwill			97,914
Current liabilities			(2,167)
Unearned revenue			(1,289)
Other assets and liabilities, net			(4,764)
Assets acquired and liabilities assumed			182,753
2024 Acquisitions | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets			1,566
2024 Acquisitions | Other intangible assets
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets			2,609
2024 Acquisitions | Customer contracts
Business Combination [Line Items]
Customer contracts			$ 72,509
FPC Holdings, LLC
Business Combination [Line Items]
Cash					$ 4,560
Accounts receivable					1,542
Materials and supplies					431
Other current assets					487
Goodwill					188,176
Customer contracts					118,000
Operating lease right-of-use assets					8,689
Operating lease liabilities					8,689
Current liabilities					(5,538)
Unearned revenue					(6,144)
Assets acquired and liabilities assumed					339,514
FPC Holdings, LLC | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets					$ 38,000
Other 2023 Acquisitions
Business Combination [Line Items]
Cash				531
Accounts receivable				1,190
Materials and supplies				592
Other current assets				198
Equipment and property				5,002
Goodwill				37,319
Current liabilities				(1,462)
Other assets and liabilities, net				(2,472)
Assets acquired and liabilities assumed				76,708
Other 2023 Acquisitions | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets				1,457
Other 2023 Acquisitions | Other intangible assets
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets				2,357
Other 2023 Acquisitions | Customer contracts
Business Combination [Line Items]
Customer contracts				$ 31,996
Initial Preliminary Allocation as of 4/1/2025 | Saela Holdings, LLC
Business Combination [Line Items]
Cash	1,506
Accounts receivable	832
Materials and supplies	573
Other current assets	414
Equipment and property	4,648
Goodwill	132,959
Operating lease right-of-use assets	991
Accounts payable	1,961
Accrued compensation and related liabilities	949
Other current liabilities	389
Operating lease liabilities	991
Assets acquired and liabilities assumed	207,133
Initial Preliminary Allocation as of 4/1/2025 | Saela Holdings, LLC | Trademarks & tradenames
Business Combination [Line Items]
Trademarks & tradenames and other intangible assets	17,300
Initial Preliminary Allocation as of 4/1/2025 | Saela Holdings, LLC | Customer contracts
Business Combination [Line Items]
Customer contracts	$ 52,200