v3.26.1
Revenues from Contracts with Customers - Summary of Company's Revenue by Major Source (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers $ 54,020 $ 45,127 $ 100,447 $ 87,730
RNG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 49,431 40,717 91,654 78,955
REG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 4,589 4,410 8,793 8,775
Natural Gas Commodity [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 4,787 13,429 11,551 26,676
Natural Gas Environmental Attributes [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 44,644 27,288 80,103 52,279
Electric Commodity [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 2,604 2,495 5,109 5,152
Electric Environmental Attributes [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 1,985 1,915 3,684 3,623
Goods transferred at a point in time [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 46,452 29,203 83,610 55,902
Goods transferred at a point in time [Member] | RNG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 44,467 27,288 79,926 52,279
Goods transferred at a point in time [Member] | REG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 1,985 1,915 3,684 3,623
Goods transferred at a point in time [Member] | Natural Gas Commodity [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 0 0 0 0
Goods transferred at a point in time [Member] | Natural Gas Environmental Attributes [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 44,467 27,288 79,926 52,279
Goods transferred at a point in time [Member] | Electric Environmental Attributes [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 1,985 1,915 3,684 3,623
Goods transferred over time [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 7,568 15,924 16,837 31,828
Goods transferred over time [Member] | RNG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 4,964 13,429 11,728 26,676
Goods transferred over time [Member] | REG [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 2,604 2,495 5,109 5,152
Goods transferred over time [Member] | Natural Gas Commodity [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 4,787 13,429 11,551 26,676
Goods transferred over time [Member] | Natural Gas Environmental Attributes [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers 177   177  
Goods transferred over time [Member] | Electric Commodity [Member]        
Disaggregation of Revenue [Line Items]        
Revenues from Contracts with Customers $ 2,604 $ 2,495 $ 5,109 $ 5,152