Basis of Presentation and Summary of Significant Accounting Policies - Accounting Policies Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Customer acquisition costs	$ 1,400,000	$ 1,400,000	$ 6,100,000
Customer acquisition costs, net	946,000	946,000	5,764,000
Customer acquisition costs, current			5,800,000
Customer acquisition costs, noncurrent	453,000	453,000	306,000
Amortization of acquisition costs		6,100,000	13,900,000	$ 18,500,000
Intangible assets, current	8,523,000	8,523,000	12,077,000
Intangible assets, non-current	5,660,000	5,660,000	5,691,000
Intangible assets	17,715,000	17,715,000
Operating lease expense		200,000	400,000	800,000
Sublease income		200,000	200,000	400,000
Goodwill impairment	0
Asset optimization revenue		57,000,000	24,800,000	62,800,000
Asset optimization cost of revenues		61,200,000	25,500,000	60,000,000
Other current assets
Finite-Lived Intangible Assets [Line Items]
Right-of-use assets	100,000	100,000	100,000
Gas balancing receivable (payable)	300,000	300,000	300,000
Other current liabilities
Finite-Lived Intangible Assets [Line Items]
Lease liabilities	100,000	100,000	200,000
Gas balancing receivable (payable)	$ 0	$ 0	(100,000)
Minimum
Finite-Lived Intangible Assets [Line Items]
Property lease term	3 years	3 years
Property and equipment estimated useful lives		2 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Property lease term	5 years	5 years
Property and equipment estimated useful lives		5 years
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortization expense		$ 12,700,000	13,600,000	18,300,000
Impairment charges		$ 0	0	0
Customer Relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Amortization period		3 years
Customer Relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization period		6 years
Trademarks
Finite-Lived Intangible Assets [Line Items]
Amortization expense		$ 1,066,000	1,110,000	1,579,000
Impairment charges		0	0	0
Intangible assets	$ 3,532,000	$ 3,532,000	$ 4,598,000	$ 5,708,000	$ 7,287,000
Trademarks | Minimum
Finite-Lived Intangible Assets [Line Items]
Amortization period		5 years
Trademarks | Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization period		10 years
Residential Customer Equivalent
Finite-Lived Intangible Assets [Line Items]
Asset acquisition, escrow deposit	$ 6,400,000	$ 6,400,000