SEGMENT REPORTING - Summary of Revenue Attributable to Services Provided by Company (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue from External Customer [Line Items]
Revenues	$ 151,222	$ 160,269	$ 154,016	$ 133,802	$ 143,795	$ 151,133	$ 144,670	$ 125,432	$ 599,309	$ 565,030	$ 546,500
Revenues percentage									100.00%	100.00%	100.00%
Collection
Revenue from External Customer [Line Items]
Revenues									$ 263,688	$ 249,640	$ 238,301
Revenues percentage									44.00%	44.20%	43.60%
Disposal
Revenue from External Customer [Line Items]
Revenues									$ 160,073	$ 154,211	$ 156,536
Revenues percentage									26.70%	27.30%	28.60%
Power generation
Revenue from External Customer [Line Items]
Revenues									$ 5,375	$ 5,921	$ 6,796
Revenues percentage									0.90%	1.00%	1.20%
Processing
Revenue from External Customer [Line Items]
Revenues									$ 7,994	$ 6,282	$ 6,061
Revenues percentage									1.30%	1.10%	1.10%
Solid waste operations
Revenue from External Customer [Line Items]
Revenues									$ 437,130	$ 416,054	$ 407,694
Revenues percentage									72.90%	73.60%	74.50%
Organics
Revenue from External Customer [Line Items]
Revenues									$ 39,815	$ 41,587	$ 39,134
Revenues percentage									6.60%	7.40%	7.20%
Customer solutions
Revenue from External Customer [Line Items]
Revenues									$ 60,057	$ 54,478	$ 53,334
Revenues percentage									10.10%	9.60%	9.80%
Recycling
Revenue from External Customer [Line Items]
Revenues									$ 62,307	$ 52,911	$ 46,338
Revenues percentage									10.40%	9.40%	8.50%