Fair Value (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The tables below set forth, by level, our financial assets that are accounted for at fair value for the respective periods. The table does not include assets and liabilities that are measured at historical cost or any basis other than fair value (in thousands):

	Fair Value Measured at Reporting Date Using
June 30, 2021	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents:
Money market funds	$	158,151	$	—	$	—	$	158,151
	$	158,151	$	—	$	—	$	158,151
Liabilities
Derivatives:
Natural gas fixed price forward contracts	$	—	$	226	$	—	$	226
Embedded EPP derivatives	—		—		7,002		7,002
Interest rate swap agreements	—		12,651		—		12,651
	$	—	$	12,877	$	7,002	$	19,879

	Fair Value Measured at Reporting Date Using
December 31, 2020	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents:
Money market funds	$	235,902	$	—	$	—	$	235,902
	$	235,902	$	—	$	—	$	235,902
Liabilities
Derivatives:
Natural gas fixed price forward contracts	$	—	$	—	$	2,574	$	2,574
Embedded EPP derivatives	—		—		5,541		5,541
Interest rate swap agreements	—		15,989		—		15,989
	$	—	$	15,989	$	8,115	$	24,104

Change in Level 3 Financial Liabilities

The changes in the Level 3 financial liabilities during the six months ended June 30, 2021 were as follows (in thousands):

	Natural Gas Fixed Price Forward Contracts		Embedded EPP Derivative Liability		Total
Liabilities at December 31, 2019	$	6,968	$	6,176	$	13,144
Settlement of natural gas fixed price forward contracts	(4,503)		—		(4,503)
Changes in fair value	109		(635)		(526)
Liabilities at December 31, 2020	2,574		5,541		8,115
Settlement of natural gas fixed price forward contracts	(1,420)		—		(1,420)
Changes in fair value	(928)		1,461		533
Transfer from Level 3 to Level 2 in fair value hierarchy	(226)		—		(226)
Liabilities at June 30, 2021	$	—	$	7,002	$	7,002

Schedule of Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation

Schedule of Fair Values and Carrying Values of Customer Receivables and Debt Instruments

The following table presents the estimated fair values and carrying values of customer receivables and debt instruments (in thousands):

	June 30, 2021				December 31, 2020
	Net Carrying Value		Fair Value		Net Carrying Value		Fair Value
Customer receivables
Customer financing receivables	$	48,060	$	40,469	$	50,746	$	42,679
Debt instruments
Recourse:
10.25% Senior Secured Notes due March 2027	66,771		74,680		68,614		71,831
2.5% Green Convertible Senior Notes due August 2025	221,879		411,698		99,394		426,229
Non-recourse:
7.5% Term Loan due September 2028	30,316		37,256		31,746		37,658
6.07% Senior Secured Notes due March 2030	75,194		86,413		77,007		89,654
LIBOR + 2.5% Term Loan due December 2021	110,273		111,340		114,138		116,113