SEGMENT REPORTING - Summary of Revenues Attributable to Services Provided by Company (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue from External Customer [Line Items]
Revenues	$ 202,667	$ 198,547	$ 574,344	$ 549,670
Solid waste operations
Revenue from External Customer [Line Items]
Revenues	153,051	152,966	429,020	416,938
Collection
Revenue from External Customer [Line Items]
Revenues	102,270	98,966	290,837	274,111
Disposal
Revenue from External Customer [Line Items]
Revenues	47,600	50,552	129,971	134,746
Power generation
Revenue from External Customer [Line Items]
Revenues	987	808	2,931	2,655
Processing
Revenue from External Customer [Line Items]
Revenues	2,194	2,640	5,281	5,426
Resource solutions operations
Revenue from External Customer [Line Items]
Revenues	49,616	45,581	145,324	132,732
Organics
Revenue from External Customer [Line Items]
Revenues	14,539	14,166	44,890	42,668
Customer solutions
Revenue from External Customer [Line Items]
Revenues	22,320	20,689	64,223	58,058
Recycling
Revenue from External Customer [Line Items]
Revenues	$ 12,757	$ 10,726	$ 36,211	$ 32,006