Fair Value - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) MW	Mar. 31, 2019 USD ($)	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash flow hedge gain to be reclassified within 12 months	$ 1,800
Gain (loss) on revaluation of embedded derivatives	284	$ (540)
Not designated as hedging instrument | Natural gas forward contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on derivative	(600)	400
Gain on the settlement of contracts	$ 1,000	$ 500
Variable Interest Entity, Primary Beneficiary | PPA IIIb
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Energy server repurchased | MW	0.4
Expected growth rate | Option Pricing Model
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivative liability, unobservable inputs	0.0700		0.0700
Price volatility | Option Pricing Model
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivative liability, unobservable inputs	0.2000		0.2000