Fair Value Measurements - Schedule of roll forward of the company's level 3 instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Change in fair value of warrant liability	$ (5,148)	$ (90,138)
Level III | Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	8,895	83,044
Obligation to issue shares of common stock to sellers of World Energy	1,526
Fair value adjustment – Quantum contingent consideration	(145)	101
Change in fair value of warrant liability		75,790
Cash settlement of Quantum liability	(950)
Fair value adjustments – Warrant liability	(1,000)
Fair value adjustments – World Energy	(390)	(565)
Fair value adjustments – World Energy	(186)
Purchase of eNow Convertible Note at fair value	5,148	0
Reserve for investment in convertible note		0
Ending balance	407	8,895
Level III | Liability | World Energy Efficiency Services, LLC
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Partial settlement of World Energy contingent consideration		(421)
Earnout – World Energy		1,000
Level III | Liability | Quantum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Adjustment - Quantum Liability	(669)
Level III | Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	0
Obligation to issue shares of common stock to sellers of World Energy	0
Fair value adjustment – Quantum contingent consideration	0	0
Change in fair value of warrant liability		0
Cash settlement of Quantum liability	0
Fair value adjustments – Warrant liability	0
Fair value adjustments – World Energy	0	0
Fair value adjustments – World Energy	0
Purchase of eNow Convertible Note at fair value	0	3,000
Reserve for investment in convertible note		(3,000)
Adjustment - Quantum Liability	0
Ending balance	$ 0	0
Level III | Assets | World Energy Efficiency Services, LLC
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Partial settlement of World Energy contingent consideration
Earnout – World Energy		$ 0