Derivative Instruments and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives reflected in the consolidated balance sheet

The estimated fair value of forward month commodity contracts (derivatives) reflected in the accompanying unaudited condensed consolidated balance sheet were as follows at the date indicated (in thousands):

	March 31, 2018
	Balance Sheet Location and Amount
	Current		Other		Current		Other
	Assets		Assets		Liabilities		Liabilities
Asset derivatives:
Fair value forward hydrocarbon commodity
contracts at gross valuation	$	312	$	—	$	—	$	—
Liability derivatives:
Fair value forward hydrocarbon commodity
contracts at gross valuation	—		—		289		—
Less counterparty offsets	—		—		—		—
As reported fair value contracts	$	312	$	—	$	289	$	—

The estimated fair value of forward month commodity contracts (derivatives) reflected in the accompanying unaudited condensed consolidated balance sheet were as follows at the date indicated (in thousands):

	December 31, 2017
	Balance Sheet Location and Amount
	Current		Other		Current		Other
	Assets		Assets		Liabilities		Liabilities
Asset derivatives:
Fair value forward hydrocarbon commodity
contracts at gross valuation	$	166	$	—	$	—	$	—
Liability derivatives:
Fair value forward hydrocarbon commodity
contracts at gross valuation	—		—		145		—
Less counterparty offsets	—		—		—		—
As reported fair value contracts	$	166	$	—	$	145	$	—

Derivatives reflected in the consolidated statement of operations

Forward month commodity contracts (derivatives) reflected in the accompanying unaudited condensed consolidated statements of operations were as follows for the periods indicated (in thousands):

	Gains (losses)
	Three Months Ended
	March 31,
	2018		2017
Revenues – marketing	$	1	$	420

Fair value assets and liabilities

The following tables set forth, by level with the Level 1, 2 and 3 fair value hierarchy, the carrying values of our financial assets and liabilities at the dates indicated (in thousands):

	March 31, 2018
	Fair Value Measurements Using
	Quoted Prices
	in Active		Significant
	Markets for		Other			Significant
	Identical Assets		Observable			Unobservable
	and Liabilities		Inputs			Inputs		Counterparty
	(Level 1)		(Level 2)			(Level 3)		Offsets		Total
Derivatives:
Current assets	$	—	$	312		$	—	$	—	$	312
Current liabilities	—		(289		)	—		—		(289		)
Net value	$	—	$	23		$	—	$	—	$	23

	December 31, 2017
	Fair Value Measurements Using
	Quoted Prices
	in Active		Significant
	Markets for		Other			Significant
	Identical Assets		Observable			Unobservable
	and Liabilities		Inputs			Inputs		Counterparty
	(Level 1)		(Level 2)			(Level 3)		Offsets		Total
Derivatives:
Current assets	$	—	$	166		$	—	$	—	$	166
Current liabilities	—		(145		)	—		—		(145		)
Net value	$	—	$	21		$	—	$	—	$	21