REVENUE RECOGNITION - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 165,649	$ 313,104
Transferred at a point-in-time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,770	15,943
Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	157,879	297,161
Collection
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	75,494	142,502
Landfill
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	24,083	44,583
Transfer
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18,756	31,921
Customer solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15,950	31,119
Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,045	22,151
Organics
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,647	26,847
Transportation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,379	10,887
Landfill gas-to-energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,295	3,094
Eastern
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	53,589	98,094
Eastern | Transferred at a point-in-time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	181	372
Eastern | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	53,408	97,722
Eastern | Collection
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	34,625	65,149
Eastern | Landfill
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,883	13,843
Eastern | Transfer
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	10,745	18,304
Eastern | Customer solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Eastern | Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Eastern | Organics
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Eastern | Transportation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Eastern | Landfill gas-to-energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	336	798
Western
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	71,043	135,783
Western | Transferred at a point-in-time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	246	614
Western | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	70,797	135,169
Western | Collection
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	40,869	77,353
Western | Landfill
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16,200	30,740
Western | Transfer
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,011	13,617
Western | Customer solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Western | Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,445	2,394
Western | Organics
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Western | Transportation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,559	9,383
Western | Landfill gas-to-energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	959	2,296
Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,600	19,757
Recycling | Transferred at a point-in-time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,618	12,875
Recycling | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,982	6,882
Recycling | Collection
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Landfill
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Transfer
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Customer solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,600	19,757
Recycling | Organics
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Transportation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Recycling | Landfill gas-to-energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	31,417	59,470
Other | Transferred at a point-in-time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,725	2,082
Other | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	29,692	57,388
Other | Collection
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other | Landfill
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other | Transfer
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other | Customer solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15,950	31,119
Other | Recycling
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other | Organics
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,647	26,847
Other | Transportation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	820	1,504
Other | Landfill gas-to-energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0