Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounts Payable and Accrued Liabilities [Line Items]
Accounts payable - trade	$ 1,399	$ 4,868
Accrued employee compensation	3,294	4,678
Other accrued liabilities	3,037	2,732
Total accounts payable and accrued liabilities	13,410	28,288
NW Lowa RNG
Accounts Payable and Accrued Liabilities [Line Items]
Accrued project costs	2,902	11,000
Net Zero Segment
Accounts Payable and Accrued Liabilities [Line Items]
Accrued project costs	$ 2,778	$ 5,010