Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

GOODWILL AND OTHER INTANGIBLE ASSETS - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) reportingUnit	Jun. 30, 2020 USD ($)
Goodwill [Line Items]
Number of reporting units \| reportingUnit			3
Goodwill impairment \| $			$ 0
Amortization of permits and other intangible assets \| $	$ 7,800,000	$ 8,800,000	15,400,000	$ 18,000,000.0
Intangible assets, written-off \| $			$ 35,400,000
Environmental Services
Goodwill [Line Items]
Number of reporting units \| reportingUnit			2
Safety-Kleen Sustainability Solutions
Goodwill [Line Items]
Number of reporting units \| reportingUnit			1