Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2013

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,
	2013			2012
Oil and gas properties:
Proved	$	2,970,047		$	2,277,811
Unproved	101,520			60,746
Total oil and gas properties	3,071,567			2,338,557
Other property and equipment	105,421			93,648
Total property and equipment	3,176,988			2,432,205
Accumulated depreciation, depletion and amortization	(939,684		)	(708,846		)
	$	2,237,304		$	1,723,359

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: 

	2013					2012			2011
	Number of Wells		Cost			Number of Wells	Cost		Number of Wells		Cost
Balance at beginning of year	1		$	4,435		—	$	—	1		$	6,180
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	—		—			—	—		(1	)	(6,180		)
Balance at end of year	—		$	—		1	$	4,435	—		$	—