Derivative Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Summary of Open Commodity Derivative Contracts

Natural Gas:

Type	Commodity Reference Price	Remaining Contract Period	Volume - MMBTU/Day		Average Price /MMBTU		Fair Value - September 30, 2017
							Asset (Liability)
Fixed price swaps
	NYMEX-Henry Hub	October 2017		575,000	$	3.17	$			3,430
	NYMEX-Henry Hub	Apr - Oct 2018		120,000	$	2.96	$			480
Type	Commodity Reference Price	Remaining Contract Period	Volume - MMBTU/Day		Floor Price ($/MMBTU)		Ceiling Price ($/MMBTU)		Fair Value - September 30, 2017
									Asset (Liability)
Collars
	NYMEX-Henry Hub	Jan - Mar 2018		40,000	$	3.23	$	3.54	$	222

Summary of Pre-tax Realized and Unrealized Gain (Loss) on Derivative Instruments

	For the Three Months					For the Nine Months
	Ended September 30,					Ended September 30,
Commodity Derivatives:	2017			2016		2017		2016
Realized gain on commodity derivatives-natural gas (1)	$	8,884		$	—	$	8,016	$	—
Unrealized (loss) gain on commodity derivatives (1)		(4,234	)		—		4,133		—
Total gain on commodity derivatives	$	4,650		$	—	$	12,149	$	—

⁽¹⁾ Included in gain on commodity derivatives in the Consolidated Statements of Operations.