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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Landfill and Lease Accounting (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) agreement	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Capitalized interest	$ 413	$ 263	$ 140
Closure and post-closure costs incurrence period	30 years
Estimate of inflation rate	1.60%
Accretion expense	$ 6,436	6,227
Number of operation and management agreements entered into | agreement	3
Closure and Post Closure Costs
Property, Plant and Equipment [Line Items]
Accretion expense	$ 6,436	6,227	$ 5,556
Surety bond	205,048	220,633
Letters of credit	$ 0	$ 0
Discount Rate | Minimum
Property, Plant and Equipment [Line Items]
Asset retirement obligation measurement input	8.20%
Discount Rate | Maximum
Property, Plant and Equipment [Line Items]
Asset retirement obligation measurement input	10.20%

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Number of Landfill Operation and Management Agreements Entered Into

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
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