Properties and Equipment (Tables)

9 Months Ended

Sep. 30, 2014

Oil and Gas Property [Abstract]

Property, Plant and Equipment

The following table presents the components of properties and equipment, net of accumulated depreciation, depletion and amortization ("DD&A"):

	September 30, 2014			December 31, 2013
	(in thousands)
Properties and equipment, net:
Crude oil and natural gas properties
Proved	$	1,976,930		$	1,677,271
Unproved	288,208			253,464
Total crude oil and natural gas properties	2,265,138			1,930,735
Equipment and other	30,428			28,832
Land and buildings	12,668			13,434
Construction in progress	146,324			41,180
Properties and equipment, at cost	2,454,558			2,014,181
Accumulated DD&A	(670,761		)	(529,543		)
Properties and equipment, net	$	1,783,797		$	1,484,638

Impairment of natural gas and crude oil properties [Table Text Block]

The following table presents impairment charges recorded for crude oil and natural gas properties:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
	(in thousands)
Continuing operations:
Impairment of proved properties	$	—	$	3,750	$	—	$	48,750
Impairment of individually significant unproved properties	—		—		—		517
Amortization of individually insignificant unproved properties	1,085		486		2,843		2,527
Other	778		—		778		—
Total continuing operations	1,863		4,236		3,621		51,794
Discontinued operations:
Impairment of individually significant unproved properties	—		154		—		462
Amortization of individually insignificant unproved properties	274		82		433		180
Total discontinued operations	274		236		433		642
Total impairment of crude oil and natural gas properties	$	2,137	$	4,472	$	4,054	$	52,436