v3.25.4
Segment Information - Summary of Operating Revenue and Significant Expenses, by Segment (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Revenue $ 176,382 $ 175,736 $ 174,904
Royalties, transportation, gathering and production fuel 32,945 31,502 34,861
Depreciation, depletion and amortization 29,972 23,515 21,158
Impairment 3,231 1,586 902
Total operating expenses 175,530 159,613 151,264
Operating income (loss) 852 16,123 23,640
Other expenses (income) 3,339 3,946 5,274
Income (loss) before income taxes (2,487) 12,177 18,366
Assets 435,460 349,015 350,238
Capital expenditures 116,542 62,323 63,091
Operating Segments [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Revenue 172,967 175,736 174,904
Payroll and related expenses 12,385 [1] 10,742 [2] 9,470 [3]
Wellfield operating and maintenance 10,255 [1] 8,641 [2] 5,739 [3]
Plant expense 3,777 [1] 3,395 [2] 3,680 [3]
Waste disposal 2,576 [1] 2,407 [2] 2,127 [3]
Preventative maintenance 18,234 [1] 17,284 [2] 14,024 [3]
Breakdown expenses 3,437 [1] 2,205 [2] 3,543 [3]
Utility expense 16,890 [1] 15,881 [2] 15,747 [3]
Royalties, transportation, gathering and production fuel 32,945 [1] 31,502 [2] 34,861 [3]
Depreciation, depletion and amortization 29,709 [1] 23,291 [2] 20,913 [3]
Impairment 3,227 [1] 1,586 [2] 902 [3]
Other operating expenses 6,229 [1],[4] 5,593 [2],[5] 5,207 [3],[6]
Total operating expenses 139,664 122,527 116,213
Operating income (loss) 33,303 53,209 58,691
Other expenses (income) 65 (1,042) (8)
Income (loss) before income taxes 33,238 54,251 58,699
Assets 393,208 294,957 250,320
Capital expenditures 116,311 61,683 63,007
Corporate and Other [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Revenue 3,415 0 0
Payroll and related expenses 19,152 23,847 20,396
Total operating expenses 35,866 [7] 37,086 [8] 35,051 [9]
Operating income (loss) (32,451) (37,086) (35,051)
Other expenses (income) 3,274 [10] 4,988 [11] 5,282 [12]
Income (loss) before income taxes (35,725) (42,074) (40,333)
Assets 42,252 54,058 99,918
Capital expenditures 231 640 84
RNG [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Impairment     777
RNG [Member] | Operating Segments [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Revenue 155,736 157,983 156,455
Payroll and related expenses 9,242 [1] 8,516 [2] 7,620 [3]
Wellfield operating and maintenance 7,220 [1] 5,104 [2] 3,659 [3]
Plant expense 2,276 [1] 2,262 [2] 2,874 [3]
Waste disposal 2,415 [1] 2,353 [2] 2,103 [3]
Preventative maintenance 15,045 [1] 13,677 [2] 10,202 [3]
Breakdown expenses 2,069 [1] 1,736 [2] 2,711 [3]
Utility expense 16,376 [1] 15,571 [2] 15,168 [3]
Royalties, transportation, gathering and production fuel 30,986 [1] 29,529 [2] 32,876 [3]
Depreciation, depletion and amortization 24,377 [1] 18,192 [2] 15,720 [3]
Impairment 3,107 [1] 843 [2] 777 [3]
Other operating expenses 4,450 [1],[4] 4,168 [2],[5] 3,458 [3],[6]
Total operating expenses 117,563 101,951 97,168
Operating income (loss) 38,173 56,032 59,287
Other expenses (income) 15 (32) 16
Income (loss) before income taxes 38,158 56,064 59,271
Assets 201,056 187,438 176,951
Capital expenditures 38,693 25,403 41,325
REG [Member] | Operating Segments [Member]      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]      
Revenue 17,231 17,753 18,449
Payroll and related expenses 3,143 [1] 2,226 [2] 1,850 [3]
Wellfield operating and maintenance 3,035 [1] 3,537 [2] 2,080 [3]
Plant expense 1,501 [1] 1,133 [2] 806 [3]
Waste disposal 161 [1] 54 [2] 24 [3]
Preventative maintenance 3,189 [1] 3,607 [2] 3,822 [3]
Breakdown expenses 1,368 [1] 469 [2] 832 [3]
Utility expense 514 [1] 310 [2] 579 [3]
Royalties, transportation, gathering and production fuel 1,959 [1] 1,973 [2] 1,985 [3]
Depreciation, depletion and amortization 5,332 [1] 5,099 [2] 5,193 [3]
Impairment 120 [1] 743 [2] 125 [3]
Other operating expenses 1,779 [1],[4] 1,425 [2],[5] 1,749 [3],[6]
Total operating expenses 22,101 20,576 19,045
Operating income (loss) (4,870) (2,823) (596)
Other expenses (income) 50 (1,010) (24)
Income (loss) before income taxes (4,920) (1,813) (572)
Assets 192,152 107,519 73,369
Capital expenditures $ 77,618 $ 36,280 $ 21,682
[1] Significant expenses regularly reviewed by the CODM.
[2] Significant expenses regularly reviewed by the CODM.
[3] Significant expenses regularly reviewed by the CODM.
[4] The majority of other operating expenses for RNG and REG are consumables, rent, environmental compliance and general and administrative expenses.
[5] The majority of other operating expenses for RNG and REG are consumables, rent, environmental compliance and general and administrative expenses.
[6] The majority of other operating expenses for RNG and REG are consumables, rent, environmental compliance and general and administrative expenses.
[7] The majority of operating expenses for Corporate and other are payroll and related expenses of $19,152, insurance of $4,646 and professional and IT fees of $4,843.
[8] The majority of operating expenses for Corporate and other are payroll and related expenses of $23,847, insurance of $5,488 and professional and IT fees of $4,141.
[9] The majority of operating expenses for Corporate and other are payroll and related expenses of $20,396, insurance of $5,951 and professional and IT fees of $5,399.
[10] The majority of other expense (income) for Corporate and other are interest expense of $4,816 and income from equity investment of ($1,485).
[11] The majority of other expense (income) for Corporate and other is interest expense of $5,276.
[12] The majority of other expense (income) for Corporate and other is interest expense of $5,753.