Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment

The following table summarizes our property and equipment as of the dates presented: 

	As of December 31,
	2014			2013
Oil and gas properties:
Proved	$	3,506,603		$	2,970,047
Unproved	125,676			101,520
Total oil and gas properties	3,632,279			3,071,567
Other property and equipment	75,073			105,421
Total property and equipment	3,707,352			3,176,988
Accumulated depreciation, depletion and amortization	(1,882,254		)	(939,684		)
	$	1,825,098		$	2,237,304

Capitalized Exploratory Well Costs, Roll Forward

The following table describes the changes in capitalized exploratory drilling costs that are pending the determination of proved reserves for the periods presented: 

	2014			2013					2012
	Number of Wells	Cost		Number of Wells		Cost			Number of Wells	Cost
Balance at beginning of year	—	$	—	1		$	4,435		—	$	—
Additions pending determination of proved reserves	—	—		—		—			1	4,435
Reclassification to wells, equipment and facilities based on the determination of proved reserves	—	—		(1	)	(4,435		)	—	—
Charged to exploration expense	—	—		—		—			—	—
Balance at end of year	—	$	—	—		$	—		1	$	4,435