Fair Value (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value, Assets and Liabilities Measured on Recurring Basis

The tables below sets forth, by level, the Company’s financial assets that were 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
	Level 1		Level 2		Level 3		Total
September 30, 2018
Assets
Cash equivalents
Money market funds	$	360,075	$	—	$	—	$	360,075
Short-term investments	4,494		—		—		4,494
Interest rate swap agreements	—		1,368		—		1,368
	$	364,569	$	1,368	$	—	$	365,937
Liabilities
Derivatives
Natural gas fixed price forward contracts	$	—	$	—	$	11,445	$	11,445
Interest rate swap agreements	—		1,845		—		1,845
	$	—	$	1,845	$	11,445	$	13,290



	Fair Value Measured at Reporting Date Using
	Level 1		Level 2		Level 3		Total
December 31, 2017
Assets
Cash equivalents
Money market funds	$	79,256	$	—	$	—	$	79,256
Short-term investments	26,816		—		—		26,816
Interest rate swap agreements	—		52		—		52
	$	106,072	$	52	$	—	$	106,124
Liabilities
Derivatives
Natural gas fixed price forward contracts	$	—	$	—	$	15,368	$	15,368
Embedded derivative on 6% promissory notes	—		—		140,771		140,771
Interest rate swap agreements	—		5,905		—		5,905
Stock warrants
Preferred stock warrants	—		—		9,825		9,825
	$	—	$	5,905	$	165,964	$	171,869

Schedule of Natural Gas Forward Contracts

The following table provides the fair value of the Company’s natural gas fixed price contracts (dollars in thousands):

September 30, 2018

December 31, 2017

Number of

Contracts

(MMBTU)²

Fair

Value

Number of
Contracts
(MMBTU)²

Fair

Value

Liabilities¹

Natural gas fixed price forward contracts (not under hedging relationships)

3,457

11,445

4,332

15,368

¹ Recorded in current liabilities and derivative liabilities in the consolidated balance sheets.

² One MMBTU is a traditional unit of energy used to describe the heat value (energy content) of fuels.

Change in Level 3 Financial Liabilities

The changes in the Level 3 financial assets were as follows (in thousands):



	Natural Gas Fixed Price Forward Contracts			Preferred Stock Warrants			Derivative Liability			Total

Balances at December 31, 2016	$	18,585		$	12,885		$	115,807		$	147,277
Settlement of natural gas fixed price forward contracts	(4,248		)	—			—			(4,248		)
Embedded derivative on notes	—			—			6,804			6,804
Changes in fair value	1,031			(3,060		)	18,160			16,131
Balances at December 31, 2017	$	15,368		$	9,825		$	140,771		$	165,964
Settlement of natural gas fixed price forward contracts	(2,871		)	—			—			(2,871		)
Embedded derivative on notes	—			—			5,533			5,533
Changes in fair value	(1,052		)	(8,943		)	30,904			20,909
Conversion of preferred stock warrants liability and derivative liability to common shares	—			(882		)	(177,208		)	(178,090		)
Balances at September 30, 2018	$	11,445		$	—		$	—		$	11,445

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):



	September 30, 2018				December 31, 2017
	Carrying Value		Fair Value		Carrying Value		Fair Value

Customer receivables:
Customer financing receivables	$	74,030	$	52,037	$	77,885	$	55,255
Debt instruments:
5.22% senior secured notes	$	81,400	$	84,314	$	89,564	$	95,114
Term loan due September 2028	36,502		42,927		36,940		46,713
Term loan due October 2020	24,021		26,562		24,364		27,206
6.07% senior secured notes	82,837		88,291		84,032		93,264
Term loan due December 2021	123,834		130,033		125,596		131,817
Term loan due November 2020	3,631		4,265		4,887		5,148
8% convertible promissory notes	—		—		244,717		211,000
5% convertible promissory notes	34,273		40,548		—		—
6% convertible promissory notes	258,862		919,260		236,724		219,094
10% notes	95,451		102,162		94,517		106,124