Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair value hierarchy of financial assets and liabilities

The following table sets forth by level within the fair value hierarchy our financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2017 and 2016:



	Fair Value Measurements Using:
	Quoted Prices in Active Markets		Significant Other Observable Inputs			Significant Unobservable Inputs
In thousands	(Level 1)		(Level 2)			(Level 3)			Total
December 31, 2017
Liabilities
Oil derivative contracts – current	$	—	$	(99,061	)	$	—		$	(99,061	)
Total Liabilities	$	—	$	(99,061	)	$	—		$	(99,061	)

December 31, 2016
Liabilities
Oil derivative contracts – current	$	—	$	(68,753	)	$	(526	)	$	(69,279	)
Total Liabilities	$	—	$	(68,753	)	$	(526	)	$	(69,279	)

Changes in fair value of Level 3 assets and liabilities

The following table summarizes the changes in the fair value of our Level 3 assets and liabilities for the years ended December 31, 2017 and 2016:



	Year Ended December 31,
In thousands	2017			2016
Fair value of Level 3 instruments, beginning of year	$	(526	)	$	52,834
Fair value adjustments on commodity derivatives	526			(2,135		)
Receipt on settlements of commodity derivatives	—			(51,225		)
Fair value of Level 3 instruments, end of year	$	—		$	(526	)

The amount of total losses for the period included in earnings attributable to the change in unrealized losses relating to assets or liabilities still held at the reporting date	$	—		$	(526	)