Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

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, 2018 and 2017:



	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, 2018
Assets
Oil derivative contracts – current	$	—	$	81,621		$	11,459	$	93,080
Oil derivative contracts – long-term	—		2,030			2,165		4,195
Total Assets	$	—	$	83,651		$	13,624	$	97,275

December 31, 2017
Liabilities
Oil derivative contracts – current	$	—	$	(99,061	)	$	—	$	(99,061	)
Total Liabilities	$	—	$	(99,061	)	$	—	$	(99,061	)

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, 2018 and 2017:



	Year Ended December 31,
In thousands	2018		2017
Fair value of Level 3 instruments, beginning of year	$	—	$	(526	)
Fair value adjustments on commodity derivatives	13,624		526
Payment on settlements of commodity derivatives	—		—
Fair value of Level 3 instruments, end of year	$	13,624	$	—

The amount of total gains for the period included in earnings attributable to the change in unrealized gains relating to assets or liabilities still held at the reporting date	$	13,624	$	—

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

The following table details fair value inputs related to implied volatilities utilized in the valuation of our Level 3 oil derivative contracts:



	Fair Value at 12/31/2018 (in thousands)		Valuation Technique	Unobservable Input	Volatility Range
Oil derivative contracts	$	13,624	Discounted cash flow / Black-Scholes	Volatility of Light Louisiana Sweet for settlement periods beginning after December 31, 2018	23.3% – 43.5%