Supplementary Oil and Natural Gas Disclosures (Tables)

12 Months Ended

Dec. 31, 2013

Supplementary Oil and Natural Gas Disclosures (Unaudited) [Abstract]

Schedule of Estimated Net Proved Reserves, Changes in Estimated Net Proved Reserves and Proved Developed Reserves

	Oil (Mbbls)		Gas (Mmcf)		Oil Equivalent (Mboe)
Estimated Proved Reserves:
December 31, 2010		17,223		61,251		27,431
Acquisitions (a)		7,987		8,640		9,427
Extensions and discoveries		2,266		4,664		3,043
Revisions		2,778		(6,678)		1,666
Production		(2,953)		(9,092)		(4,468)
December 31, 2011		27,301		58,785		37,099
Acquisitions (b)		16,430		115,876		35,742
Extensions and discoveries (c)		6,388		10,241		8,095
Revisions		1,128		4,033		1,800
Production		(3,805)		(8,996)		(5,304)
December 31, 2012		47,442		179,939		77,432
Acquisitions		366		209		401
Sales		(1,415)		(916)		(1,568)
Extensions and discoveries (d)		7,354		20,247		10,729
Revisions		3,952		(10,128)		2,264
Production		(6,182)		(15,767)		(8,810)
December 31, 2013		51,517		173,584		80,448
Proved developed reserves:
December 31, 2011		24,791		52,739		33,581
December 31, 2012		37,908		120,687		58,022
December 31, 2013		39,439		107,687		57,387
Proved undeveloped reserves:
December 31, 2011		2,510		6,046		3,518
December 31, 2012		9,534		59,252		19,409
December 31, 2013		12,078		65,897		23,061

Capitalized Costs for Oil and Natural Gas Producing Activities

	Year Ended December 31,
	2013		2012
	(In thousands)
Proved properties	$	2,307,891	$	1,982,657
Unproved properties		39,191		36,992
Accumulated depreciation, depletion and amortization		(614,068)		(424,520)
Net capitalized costs	$	1,733,014	$	1,595,129

Cost Incurred Associated with Finding, Acquiring and Developing Proved Oil and Natural Gas Reserves

	Year Ended December 31,
	2013		2012		2011
	(In thousands)
Acquisitions — Proved (1)	$	46,047	$	706,322	$	261,812
Acquisitions — Unproved		2,200		7,496		14
Exploration		46,100		43,338		17,129
Development (2)		303,245		180,938		83,577
Costs incurred	$	397,592	$	938,094	$	362,532

Standardized Measure of Discounted Future Cash Flows Relating to Proved Oil and Natural Gas Reserves Disclosure

	Year Ended December 31,
	2013		2012
	(In thousands)
Future cash inflows	$	5,937,536	$	5,401,290
Future production costs		(1,957,868)		(1,823,303)
Future development costs (1)		(1,085,440)		(936,580)
Future income taxes		(641,536)		(537,546)
Future net cash flows after income taxes		2,252,692		2,103,861
10% annual discount for estimated timing of cash flows		(603,614)		(529,579)
Standardized measure of discounted future net cash flows	$	1,649,078	$	1,574,282

Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows Applicable to Proved Oil and Natural Gas Reserves

	Year Ended December 31,
	2013		2012
	(In thousands)
Beginning of the period	$	1,574,282	$	876,169
Sales and transfers of oil and natural gas produced, net of production costs		(513,906)		(317,059)
Net changes in prices and production costs		96,751		(244,824)
Purchase of minerals in place		26,708		797,085
Sales of minerals in place		(64,539)		-
Extensions, discoveries and improved recoveries, net of future production costs		363,493		452,258
Revision of quantity estimates		84,490		55,133
Previously estimated development costs incurred during the period		33,920		39,321
Changes in estimated future development costs		18,229		746
Changes in production rates (timing) and other		(113,022)		(14,157)
Accretion of discount		197,927		110,070
Net change in income taxes		(55,255)		(180,460)
Net increase (decrease)		74,796		698,113
End of period	$	1,649,078	$	1,574,282

Oil and Natural Gas Computed Price Used in Computation of Discounted Future Net Cash Flows

	2013		2012
per barrel of oil	$	105.30	$	105.13
per Mcf for natural gas	$	3.73	$	2.92