Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2012

Property and Equipment [Abstract]

Summary of the Company's property and equipment

	December 31,
	2012			2011
Oil and natural gas properties
Evaluated (subject to amortization)	$	763,527		$	423,945
Unproved and unevaluated (not subject to amortization)
Incurred in 2012		36,488			–
Incurred in 2011		24,138			60,934
Incurred in 2010		70,417			80,593
Incurred in 2009 and prior		18,632			21,071
Total unproved and unevaluated		149,675			162,598
Total oil and natural gas properties		913,202			586,543
Accumulated depletion		(344,609	)		(201,543	)
Net oil and natural gas properties		568,593			385,000
Other property and equipment
Computer equipment		834			787
Furniture		793			458
Software		1,355			1,111
Other equipment		196			194
Leasehold improvements		644			627
Support equipment and facilities		23,436			15,587
Total other property and equipment		27,258			18,764
Accumulated depreciation		(4,761	)		(3,899	)
Net other property and equipment		22,497			14,865
Net property and equipment	$	591,090		$	399,865

Breakdown of the Company's unproved and unevaluated property costs not subject to amortization

Description	2012		2011		2010		2009 and prior		Total
Costs incurred for
Property acquisition	$	29,165	$	21,748	$	70,417	$	18,632	$	139,962
Exploration wells		4,680		1,932		–		–		6,612
Development wells		2,573		–		–		–		2,573
Capitalized interest		70		458		–		–		528
Total	$	36,488	$	24,138	$	70,417	$	18,632	$	149,675