COMMITMENTS AND CONTINGENCIES - Additional Information (Detail)		1 Months Ended
	Apr. 28, 2017 USD ($)	Apr. 30, 2011 USD ($)	May 31, 2009 USD ($)	Apr. 26, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 29, 2016	Dec. 20, 2000 a
Potsdam Environmental Remediation Liability
Loss Contingencies [Line Items]
Scrap yard and solid waste transfer station (in acres) | a								25
Estimate of total undiscounted costs associated with implementing the preferred remedies		$ 12,130,000	$ 10,219,000
Remediation activities, participant share percentage							15.00%
Risk free interest rate					1.50%
Accrual for Environmental Loss Contingencies					$ 5,866,000	$ 5,866,000
Subsequent Event | Notice of Intent to Sue under the Resource Conservation and Recovery Act
Loss Contingencies [Line Items]
Shared costs				$ 5,000,000
Subsequent Event | MADEP and Casella Waste System | Notice of Intent to Sue under the Resource Conservation and Recovery Act
Loss Contingencies [Line Items]
Shared costs				$ 10,000,000
Subsequent Event | 21E Settlement and Water System Construction Funding Agreement | Bonds
Loss Contingencies [Line Items]
Bond period	20 years
Aggregate principal amount	$ 5,000,000
Town of Southbridge, Massachusetts Landfill
Loss Contingencies [Line Items]
Investigative expenditure incurred, expect recovery amount					$ 2,809,000