v3.26.1
Segment Information - Summary of Operating Revenue and Significant Expenses, by Segment (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]          
Revenue $ 54,020 $ 45,127 $ 100,447 $ 87,730  
Royalties, transportation, gathering and production fuel 8,814 9,168 16,851 16,739  
Depreciation, depletion and amortization 7,904 7,029 16,277 13,293  
Impairment 650 377 1,093 2,424  
Total operating expenses 54,095 47,482 102,122 89,676  
Operating loss (75) (2,355) (1,675) (1,946)  
Other expenses (income) (2,291) 1,256 (3,598) 2,446  
Income (loss) before income taxes 2,216 (3,611) 1,923 (4,392)  
Assets 470,706 382,492 470,706 382,492 $ 435,460
Capital expenditures 24,693 33,666 55,560 45,298  
Operating Segments [Member]          
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]          
Revenue 45,441 45,127 87,632 87,730  
Payroll and related expenses 3,892 [1] 3,126 [2] 7,575 [3] 6,219 [4]  
Wellfield operating and maintenance 2,737 [1] 2,615 [2] 5,226 [3] 4,985 [4]  
Plant expense 999 [1] 1,086 [2] 1,836 [3] 2,031 [4]  
Waste disposal 728 [1] 611 [2] 1,298 [3] 1,194 [4]  
Preventative maintenance 5,633 [1] 7,647 [2] 10,332 [3] 11,805 [4]  
Breakdown expenses 712 [1] 890 [2] 1,243 [3] 1,783 [4]  
Utility expense 3,933 [1] 4,014 [2] 8,477 [3] 8,054 [4]  
Royalties, transportation, gathering and production fuel 8,814 [1] 9,168 [2] 16,851 [3] 16,739 [4]  
Depreciation, depletion and amortization 7,836 [1] 6,959 [2] 16,138 [3] 13,170 [4]  
Impairment 650 [1] 377 [2] 1,093 [3] 2,424 [4]  
Other operating expenses 1,996 [1],[5] 1,754 [2],[6] 3,480 [7] 3,098 [8]  
Total operating expenses 37,930 38,247 73,549 71,502  
Operating loss 7,511 6,880 14,082 16,228  
Other expenses (income) 13 30 24 46  
Income (loss) before income taxes 7,498 6,850 14,058 16,182  
Assets 432,869 339,424 432,869 339,424  
Capital expenditures 24,619 33,528 55,437 45,079  
Corporate and Other [Member]          
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]          
Revenue 8,579 0 12,816 0  
Payroll and related expenses 4,488 6,296 8,938 11,454  
Total operating expenses 16,165 [9] 9,235 [10] 28,573 [11] 18,174 [12]  
Operating loss (7,586) (9,235) (15,757) (18,174)  
Other expenses (income) (2,304) [13] 1,226 [14] (3,622) [15] (2,400) [16]  
Income (loss) before income taxes (5,282) (10,461) (12,135) (20,574)  
Assets 37,837 43,068 37,837 43,068  
Capital expenditures 74 138 123 219  
RNG [Member] | Operating Segments [Member]          
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]          
Revenue 40,936 40,829 79,010 79,280  
Payroll and related expenses 2,406 [1] 2,451 [2] 4,778 [3] 4,861 [4]  
Wellfield operating and maintenance 2,217 [1] 1,762 [2] 4,137 [3] 3,416 [4]  
Plant expense 653 [1] 710 [2] 1,215 [3] 1,329 [4]  
Waste disposal 688 [1] 584 [2] 1,198 [3] 1,153 [4]  
Preventative maintenance 4,192 [1] 5,734 [2] 7,886 [3] 9,284 [4]  
Breakdown expenses 615 [1] 547 [2] 898 [3] 992 [4]  
Utility expense 3,802 [1] 3,934 [2] 8,200 [3] 7,860 [4]  
Royalties, transportation, gathering and production fuel 8,293 [1] 8,668 [2] 15,875 [3] 15,783 [4]  
Depreciation, depletion and amortization 6,992 [1] 5,631 [2] 14,081 [3] 10,531 [4]  
Impairment 439 [1] 347 [2] 748 [3] 2,340 [4]  
Other operating expenses 995 [1],[5] 1,233 [2],[6] 1,609 [7] 2,134 [8]  
Total operating expenses 31,292 31,601 60,625 59,683  
Operating loss 9,644 9,228 18,385 19,597  
Other expenses (income) 1 1 (2) 9  
Income (loss) before income taxes 9,643 9,227 18,387 19,588  
Assets 188,154 203,615 188,154 203,615  
Capital expenditures 2,221 10,362 4,790 17,930  
REG [Member] | Operating Segments [Member]          
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]          
Revenue 4,505 4,298 8,621 8,450  
Payroll and related expenses 1,486 [1] 675 [2] 2,797 [3] 1,358 [4]  
Wellfield operating and maintenance 520 [1] 853 [2] 1,089 [3] 1,569 [4]  
Plant expense 346 [1] 376 [2] 621 [3] 702 [4]  
Waste disposal 40 [1] 27 [2] 100 [3] 41 [4]  
Preventative maintenance 1,441 [1] 1,913 [2] 2,446 [3] 2,521 [4]  
Breakdown expenses 97 [1] 343 [2] 345 [3] 791 [4]  
Utility expense 131 [1] 80 [2] 277 [3] 194 [4]  
Royalties, transportation, gathering and production fuel 521 [1] 500 [2] 976 [3] 956 [4]  
Depreciation, depletion and amortization 844 [1] 1,328 [2] 2,057 [3] 2,639 [4]  
Impairment 211 [1] 30 [2] 345 [3] 84 [4]  
Other operating expenses 1,001 [1],[5] 521 [2],[6] 1,871 [7] 964 [8]  
Total operating expenses 6,638 6,646 12,924 11,819  
Operating loss (2,133) (2,348) (4,303) (3,369)  
Other expenses (income) 12 29 26 37  
Income (loss) before income taxes (2,145) (2,377) (4,329) (3,406)  
Assets 244,715 135,809 244,715 135,809  
Capital expenditures $ 22,398 $ 23,166 $ 50,647 $ 27,149  
[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] Significant expenses regularly reviewed by the CODM.
[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 other operating expenses for RNG and REG are consumables, rent, environmental compliance and general and administrative expenses.
[8] The majority of other operating expenses for RNG and REG are consumables, rent, environmental compliance and general and administrative expenses.
[9] The majority of operating expenses for Corporate and other are payroll and related expenses of $4,488, insurance of $1,107 and professional and IT fees of $1,274.
[10] The majority of operating expenses for Corporate and other are payroll and related expenses of $6,296, insurance of $1,186 and professional and IT fees of $977.
[11] The majority of operating expenses for Corporate and other are payroll and related expenses of $8,938, insurance of $2,177 and professional and IT fees of $2,991.
[12] The majority of operating expenses for Corporate and other are payroll and related expenses of $11,454, insurance of $2,517 and professional and IT fees of $2,337.
[13] The majority of other expense (income) for Corporate and other are interest expense of $1,531 and income from equity investment of ($3,772).
[14] The majority of other expense for Corporate and other is interest expense of $1,216.
[15] The majority of other expense (income) for Corporate and other is interest expense of $2,866 and income from equity investment of ($7,092).
[16] The majority of other expense for Corporate and other is interest expense of $2,459.