Segment Reporting - Summary of Financial Information by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 144,670	$ 143,714	$ 270,103	$ 260,292
Depreciation and amortization	15,802	16,241	30,255	29,990
Operating income (loss)	15,596	11,342	17,570	14,468
Total assets	631,621	640,177	631,621	640,177	$ 633,669
Eastern Region [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	7,138	6,752	13,327	11,990
Operating income (loss)	3,079	3,186	2,291	2,700
Total assets	208,316	207,507	208,316	207,507
Western Region [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	6,908	7,674	13,398	14,412
Operating income (loss)	10,175	7,684	13,169	12,679
Total assets	319,480	323,746	319,480	323,746
Recycling [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	1,040	1,110	2,132	2,226
Operating income (loss)	468	(401)	(606)	(2,411)
Total assets	48,782	50,457	48,782	50,457
Other [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	716	705	1,398	1,362
Operating income (loss)	1,874	873	2,716	1,500
Total assets	55,043	58,467	55,043	58,467
Outside Revenues [Member]
Segment Reporting Information [Line Items]
Revenues	144,670	143,714	270,103	260,292
Outside Revenues [Member] | Eastern Region [Member]
Segment Reporting Information [Line Items]
Revenues	45,405	43,822	84,392	77,090
Outside Revenues [Member] | Western Region [Member]
Segment Reporting Information [Line Items]
Revenues	59,460	61,686	111,922	111,043
Outside Revenues [Member] | Recycling [Member]
Segment Reporting Information [Line Items]
Revenues	12,816	11,462	23,454	21,756
Outside Revenues [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues	26,989	26,744	50,335	50,403
Inter-Company Revenue [Member]
Segment Reporting Information [Line Items]
Revenues	(30,287)	(30,428)	(55,586)	(53,066)
Inter-Company Revenue [Member] | Eastern Region [Member]
Segment Reporting Information [Line Items]
Revenues	11,692	11,401	21,229	19,417
Inter-Company Revenue [Member] | Western Region [Member]
Segment Reporting Information [Line Items]
Revenues	17,889	18,504	32,740	32,901
Inter-Company Revenue [Member] | Recycling [Member]
Segment Reporting Information [Line Items]
Revenues	302	253	933	257
Inter-Company Revenue [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues	$ 404	$ 270	$ 684	$ 491