REVENUES (Tables)

6 Months Ended

Jun. 30, 2024

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregation of Revenue

The following tables present the Company's third-party revenue disaggregated by source of revenue and geography (in thousands):

	Three Months Ended June 30, 2024
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	1,175,328	$	232,789	$	99	$	1,408,216
Canada	121,970		22,533		—		144,503
Total third-party revenues	$	1,297,298	$	255,322	$	99	$	1,552,719
Sources of Revenue
Technical Services	$	443,668	$	—	$	—	$	443,668
Industrial Services and Other	359,471		—		99		359,570
Field and Emergency Response Services	252,893		—		—		252,893
Safety-Kleen Environmental Services	241,266		58,421		—		299,687
Safety-Kleen Oil	—		196,901		—		196,901
Total third-party revenues	$	1,297,298	$	255,322	$	99	$	1,552,719

	Three Months Ended June 30, 2023
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	1,041,739	$	212,994	$	116	$	1,254,849
Canada	119,743		23,308		—		143,051
Total third-party revenues	$	1,161,482	$	236,302	$	116	$	1,397,900
Sources of Revenue
Technical Services	$	389,908	$	—	$	—	$	389,908
Industrial Services and Other	399,545		—		116		399,661
Field and Emergency Response Services	154,359		—		—		154,359
Safety-Kleen Environmental Services	217,670		62,452		—		280,122
Safety-Kleen Oil	—		173,850		—		173,850
Total third-party revenues	$	1,161,482	$	236,302	$	116	$	1,397,900

	Six Months Ended June 30, 2024
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	2,228,786	$	426,701	$	201	$	2,655,688
Canada	229,791		43,935		—		273,726
Total third-party revenues	$	2,458,577	$	470,636	$	201	$	2,929,414
Sources of Revenue
Technical Services	$	851,159	$	—	$	—	$	851,159
Industrial Services and Other	718,868		—		201		719,069
Field and Emergency Response Services	416,362		—		—		416,362
Safety-Kleen Environmental Services	472,188		111,442		—		583,630
Safety-Kleen Oil	—		359,194		—		359,194
Total third-party revenues	$	2,458,577	$	470,636	$	201	$	2,929,414

	Six Months Ended June 30, 2023
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	2,000,323	$	434,765	$	223	$	2,435,311
Canada	222,141		47,835		—		269,976
Total third-party revenues	$	2,222,464	$	482,600	$	223	$	2,705,287
Sources of Revenue
Technical Services	$	756,417	$	—	$	—	$	756,417
Industrial Services and Other	735,924		—		223		736,147
Field and Emergency Response Services	302,445		—		—		302,445
Safety-Kleen Environmental Services	427,678		112,011		—		539,689
Safety-Kleen Oil	—		370,589		—		370,589
Total third-party revenues	$	2,222,464	$	482,600	$	223	$	2,705,287

Schedule of Contract Balances

(in thousands)	June 30, 2024		December 31, 2023
Receivables	$	1,089,832	$	983,111
Contract assets (unbilled receivables)	187,148		107,859
Contract liabilities (deferred revenue)	108,035		95,230