Deferred Revenue from Volumetric Production Payment (Tables)

12 Months Ended

Dec. 31, 2016

Deferred Revenue Disclosure [Abstract]

Schedule of changes in deferred revenue from the VPP

The following table reflects the changes in deferred revenue during the years ended December 31, 2016 and 2015:

	2016			2015
	(In thousands)
Beginning of year	$	5,470		$	23,129
Deferred revenue from VPP	—			2,866
Amortization of deferred revenue from VPP	(1,479		)	(6,822		)
Termination of VPP	—			(13,703		)
End of year	$	3,991		$	5,470