Suspended Well Costs Suspended Well Costs (Tables)

12 Months Ended

Dec. 31, 2016

Suspended Well Costs [Abstract]

Capitalized Exploratory Well Costs, Roll Forward [Table Text Block]

The following table reflects the net changes in capitalized exploratory well costs during 2016, 2015, and 2014. The table does not include amounts that were capitalized and either subsequently expensed or reclassified to producing well costs in the same year:

	For the Years Ended December 31,
	2016			2015			2014
	(in thousands)
Beginning balance on January 1,	$	11,952		$	43,589		$	34,527
Additions to capitalized exploratory well costs pending the determination of proved reserves	19,846			11,952			43,589
Divestitures	—			(809		)	—
Reclassifications to wells, facilities, and equipment based on the determination of proved reserves	(11,952		)	(18,485		)	(33,340		)
Capitalized exploratory well costs charged to expense	—			(24,295		)	(1,187		)
Ending balance at December 31,	$	19,846		$	11,952		$	43,589