LONG-TERM DEBT - Summary of Components of Long-Term Debt and Capital Leases by Debt Instrument (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt and capital lease	$ 519,158	$ 525,583
Less—unamortized discount and debt issuance costs	16,550	16,936
Long-term debt and capital leases less unamortized discount and debt issuance costs	502,608	508,647
Less—current maturities of long-term debt	5,016	4,686
Non current portion of long term debt and capital lease obligation	497,592	503,961
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt and capital lease	55,600	62,600
Less—unamortized discount and debt issuance costs	4,452	4,965
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014 due December 2044 - fixed rate interest period through 2019; bearing interest at 3.75%
Debt Instrument [Line Items]
Long-term debt and capital lease	25,000	25,000
Less—unamortized discount and debt issuance costs	1,128	1,221
New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014R-2 due December 2044 - fixed rate interest period through 2026; bearing interest at 3.125%
Debt Instrument [Line Items]
Long-term debt and capital lease	15,000	15,000
Less—unamortized discount and debt issuance costs	541	571
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 due January 2025 - fixed rate interest period through 2025; bearing interest at 5.25%
Debt Instrument [Line Items]
Long-term debt and capital lease	25,000	0
Less—unamortized discount and debt issuance costs	645	0
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015 due August 2035 - fixed rate interest period through 2025; bearing interest at 5.125%
Debt Instrument [Line Items]
Long-term debt and capital lease	15,000	15,000
Less—unamortized discount and debt issuance costs	726	760
Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2013 due April 2036 - fixed rate interest period through 2018; bearing interest at 4.75%
Debt Instrument [Line Items]
Long-term debt and capital lease	16,000	16,000
Less—unamortized discount and debt issuance costs	589	605
Business Finance Authority of the State of New Hampshire Solid Waste Disposal Revenue Bonds Series 2013 due April 2029 - fixed rate interest period through 2019; bearing interest at 4.00%
Debt Instrument [Line Items]
Long-term debt and capital lease	11,000	11,000
Less—unamortized discount and debt issuance costs	499	563
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-2 due January 2025 - fixed rate interest period through 2017; bore interest at 6.25%
Debt Instrument [Line Items]
Long-term debt and capital lease	0	21,400
Less—unamortized discount and debt issuance costs	0	502
Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-1; letter of credit backed due January 2025 - bore interest at SIFMA Index
Debt Instrument [Line Items]
Long-term debt and capital lease	0	3,600
Less—unamortized discount and debt issuance costs	0	31
Capital leases maturing through April 2023; bearing interest at up to 7.70%
Debt Instrument [Line Items]
Long-term debt and capital lease	5,363	5,534
Notes payable maturing through June 2027; bearing interest at up to 7.00%
Debt Instrument [Line Items]
Long-term debt and capital lease	2,945	449
Term Loan B Facility due October 2023; bearing interest at LIBOR plus 2.75% and 3.00%, respectively | Secured Debt
Debt Instrument [Line Items]
Long-term debt and capital lease	348,250	350,000
Less—unamortized discount and debt issuance costs	7,970	7,718
Unamortized discount	$ 1,598	$ 1,712