Derivatives, Hedges, Financial Instruments and Carbon Credits (Tables)

9 Months Ended

Sep. 30, 2018

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following details our assets and liabilities that are measured at fair value on a recurring basis at September 30, 2018 and December 31, 2017:

				Fair Value Measurements at September 30, 2018 Using
Description	Total Fair Value at September 30, 2018			Quoted Prices in Active Markets for Identical Contracts (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Total Fair Value at December 31, 2017
	(In Thousands)

Assets - Supplies, prepaid items and other:
Carbon credits	$	1,147		$	—	$	—	$	1,147		$	—
Total	$	1,147		$	—	$	—	$	1,147		$	—

Liabilities - Current and noncurrent accrued and other liabilities:
Contractual obligations - carbon credits	$	(1,147	)	$	—	$	—	$	(1,147	)	$	—
Embedded derivative	$	(2,970	)	$	—	$	—	$	(2,970	)	$	(2,660	)
Total	$	(4,117	)	$	—	$	—	$	(4,117	)	$	(2,660	)

Reconciliation of Beginning and Ending Balances for Assets and Liabilities Measured at Fair Value on Recurring Basis

The following is a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3):

	Assets				Liabilities						Assets						Liabilities
	Three Months Ended				Three Months Ended						Nine Months Ended						Nine Months Ended
	September 30,				September 30,						September 30,						September 30,
	2018		2017		2018			2017			2018			2017			2018			2017
	(In Thousands)
Beginning balance	$	—	$	—	$	(1,838	)	$	(3,137	)	$	—		$	—		$	(2,660	)	$	(2,557	)
Transfers into Level 3		—		—		—			—			—			—			—			—
Transfers out of Level 3		—		—		—			—			—			—			—			—
Total realized and unrealized gains (losses) included in operating results		1,147		1,164		(2,279	)		(438	)		1,681			2,031			(1,656	)		(1,705	)
Purchases		—		—		—			—			—			—			—			—
Issuances		—		—		—			—			—			—			(229	)		—
Sales		—		—		—			—			(534	)		(867	)		—			—
Settlements		—		—		—			—			—			—			428			687
Ending balance	$	1,147	$	1,164	$	(4,117	)	$	(3,575	)	$	1,147		$	1,164		$	(4,117	)	$	(3,575	)

Total gains (losses) for the period included in operating results attributed to the change in unrealized gains or losses on assets and liabilities still held at the reporting date	$	1,147	$	1,164	$	(2,278	)	$	(438	)	$	1,147		$	1,164		$	(1,227	)	$	(1,018	)

Net Gains (Losses) Included in Operating Results and Statement of Operations Classifications

Net gains (losses) included in operating results and the statement of operations classifications are as follows:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2018			2017			2018			2017
	(In Thousands)
Total net gains (losses) included in operating results:
Other income - Carbon credits	$	1,147		$	1,164		$	1,681		$	2,031
Other expense - Contractual obligations relating to carbon credits		(1,147	)		(1,164	)		(1,575	)		(1,851	)
Non-operating other income (expense) - embedded derivative		(1,132	)		726			(81	)		146
Total net gains (losses) included in operating results	$	(1,132	)	$	726		$	25		$	326

Schedule of Carrying Values and Estimated Fair Values of Financial Instruments

At September 30, 2018 and December 31, 2017, we did not have any financial instruments with fair values significantly different from their carrying amounts (excluding issuance costs, if applicable), except for the Senior Secured Notes as shown below.

	September 30, 2018
	Carrying		Estimated
	Amount		Fair Value
	(In Millions)
Senior Secured Notes (1)	$	400	$	421

(1)	Based on a quoted price of 105.25 at September 30, 2018. These Senior Secured Notes were issued on April 25, 2018.