Investments in Other Entities and Noncontrolling Interest in a Subsidiary - NG Advantage (Details) - USD ($) $ in Thousands					1 Months Ended				4 Months Ended	12 Months Ended
	Feb. 29, 2020	Feb. 06, 2020	Oct. 01, 2018	Feb. 28, 2018	Feb. 28, 2019	Jan. 31, 2019	Dec. 31, 2018	Nov. 30, 2018	Feb. 28, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 24, 2020	Oct. 14, 2014
Business Acquisition [Line Items]
Payments to acquire additional controlling interest										$ 78,919	$ 650
Proceeds from debt instruments										4,400	65,860	$ 15,294
Outstanding balance										36,060	85,680
Income (loss) attributable to noncontrolling interest										(1,009)	(1,665)	(7,162)
Investments Carried at Cost
Investments carried at cost										8,000
NG Advantage
Business Acquisition [Line Items]
Ownership interest before transaction (as a percent)				53.30%
Ownership interest after transaction (as a percent)				53.50%
Income (loss) attributable to noncontrolling interest										(1,000)	(1,700)	(7,200)
Noncontrolling interest, fair value										8,300	$ 9,300
BP Products North America | NG Advantage | Long-Term Natural Gas Purchase Contracts
Business Acquisition [Line Items]
Contingent consideration, liability (up to)				$ 30,000									$ 15,000
NG Advantage
Business Acquisition [Line Items]
Purchase of interest by parent, shares purchased (in shares)			1,000,001
Payments to acquire additional controlling interest			$ 5,000
Ownership interest before transaction (as a percent)		64.60%	53.50%
Ownership interest after transaction (as a percent)		93.20%	61.70%						64.60%		93.30%
Debt Instrument, Face Amount										5,000
NG Advantage | November 2019 Convertible Note
Business Acquisition [Line Items]
Debt Instrument, Face Amount												$ 26,700
Number of common units to be called by warrants (in shares)												2,086,879
NG Advantage | Payment Obligations
Business Acquisition [Line Items]
Purchase of interest by parent, shares purchased (in shares)				19,660	100,000	100,000	100,000	100,000	400,000
NG Advantage | Common unit purchase agreement
Business Acquisition [Line Items]
Ownership interest acquired														53.30%
Issuance of equity by subsidiary to parent (in shares)	283,019
NG Advantage | Clean Energy Fuels Corp | Convertible Debt
Business Acquisition [Line Items]
Outstanding balance										$ 18,400