Segment Information - Summary of Reconciliation of the Company's Reportable Segments' Net Income from Continuing Operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Revenue									$ 148,127	$ 100,383	$ 105,714
Net income (loss)	$ 5,493	$ 8,896	$ (4,652)	$ (14,265)	$ 2,454	$ (2,084)	$ (1,583)	$ 5,816	(4,528)	4,603	5,820
EBITDA									25,430	25,063	30,802
Net loss (gain) of sale of assets									822	320	10
Adjusted EBITDA									27,949	26,049	33,111
Total Assets	286,480				253,356				286,480	253,356	243,613
Capital expenditure									9,986	17,646	45,610
Depreciation and amortization									22,869	22,117	19,760
Interest expense									2,928	4,339	5,576
Income tax expense (benefit)									4,161	(5,996)	(354)
Impairment loss									1,191	278	2,443
Loss on extinguishment of debt									154
Transaction costs									352		202
Non-cash hedging charges										388	(252)
Equity (income) loss of nonconsolidated investments											(94)
RNG [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Revenue									131,803	83,236	84,157
Net income (loss)									49,387	22,068	25,640
EBITDA									66,549	36,920	37,342
Net loss (gain) of sale of assets									822	299	(2)
Adjusted EBITDA									67,812	37,219	39,019
Total Assets	150,472				159,899				150,472	159,899	136,068
Capital expenditure									7,647	14,071	33,509
Depreciation and amortization									17,162	14,852	11,702
Impairment loss									441		1,690
Transaction costs											83
Equity (income) loss of nonconsolidated investments											(94)
REG [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Revenue									15,449	16,665	19,859
Net income (loss)									(3,129)	(2,713)	(1,635)
EBITDA									2,399	4,649	5,428
Net loss (gain) of sale of assets										21
Adjusted EBITDA									3,149	4,948	6,185
Total Assets	57,980				52,539				57,980	52,539	83,051
Capital expenditure									2,296	3,513	11,731
Depreciation and amortization									5,528	7,086	7,878
Interest expense											7
Income tax expense (benefit)									0	276	(822)
Impairment loss									750	278	753
Transaction costs											4
Non-cash hedging charges										388
Corporate [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Revenue									875	482	1,698
Net income (loss)									(50,786)	(14,752)	(18,185)
EBITDA									(43,518)	(16,506)	(11,968)
Net loss (gain) of sale of assets											12
Adjusted EBITDA									(43,012)	(16,118)	(12,093)
Total Assets	$ 78,028				$ 40,918				78,028	40,918	24,494
Capital expenditure									43	62	370
Depreciation and amortization									179	179	180
Interest expense									2,928	4,339	5,569
Income tax expense (benefit)									4,161	$ (6,272)	468
Loss on extinguishment of debt									154
Transaction costs									$ 352		115
Non-cash hedging charges											$ (252)