Revenues from Contracts with Customers - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue Benchmark [Member] | Product Concentration Risk [Member] | Counterparty Sharing Arrangement [Member]
Disaggregation of Revenue [Line Items]
Revenue Performance obligation satisfied to segments, Percentage	10.00%	6.00%	6.00%
Transferred Over Time Member | Renewable Natural Gas and Renewable Electricity Generation | Revenue From Contract With Customer Segment Bench mark Member | Renewable Energy [Member] | Customer Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Revenue Performance obligation satisfied to segments, Percentage	28.00%	32.00%	37.00%
Transferred At Point In Time Member | Revenue from Contract with Customer, Product and Service Benchmark [Member] | Electric Environmental Attributes [Member] | Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Revenue Performance obligation satisfied to segments, Percentage	72.00%	68.00%	63.00%