Revenues from Contracts with Customers and Other Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 16,915	$ 17,200
Renewable natural gas
Disaggregation of Revenue [Line Items]
Total operating revenue	691	659
Environmental Attributes
Disaggregation of Revenue [Line Items]
Total operating revenue	15,105	14,798
Licensing and development revenue
Disaggregation of Revenue [Line Items]
Total operating revenue	800	1,300
Other revenue
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 319	$ 443