$AR
ANTERO RESOURCES Corp Stock $ar

$ar Overview Financials Valuation SEC Filings Company Website

2014 Q1 Form 10-K Financial Statement

#000104746914001424 Filed on February 27, 2014

Income Statement

Concept	2014 Q1	2013 Q4	2013 Q3
Revenue	$165.0M	$480.0M	$384.5M
YoY Change	168.46%	104.18%	-517.79%
Cost Of Revenue	$109.4M	$94.50M	$72.90M
YoY Change	115.78%	106.33%	139.8%
Gross Profit	$58.80M	$385.5M	$311.6M
YoY Change	444.44%	103.65%	-354.78%
Gross Profit Margin	35.64%	80.31%	81.04%
Selling, General & Admin	$63.00M	$384.7M	$14.40M
YoY Change	396.06%	2708.03%	21.01%
% of Gross Profit	107.14%	99.79%	4.62%
Research & Development	$7.000M	$5.200M	$5.400M
YoY Change	59.09%	-23.53%	68.75%
% of Gross Profit	11.9%	1.35%	1.73%
Depreciation & Amortization	$91.21M	$75.50M	$65.70M
YoY Change	125.96%	105.72%	144.61%
% of Gross Profit	155.11%	19.58%	21.08%
Operating Expenses	$269.1M	$561.3M	$161.9M
YoY Change	144.77%	405.35%	116.35%
Operating Profit	-$104.1M	-$81.32M	$222.6M
YoY Change	114.73%	-165.57%	-233.4%
Interest Expense	$31.34M	-$35.80M	$37.44M
YoY Change	4.72%	35.09%	66.77%
% of Operating Profit			16.82%
Other Income/Expense, Net
YoY Change
Pretax Income	-$135.4M	-$159.7M	$185.2M
YoY Change	72.74%	-263.79%	-197.8%
Income Tax	-$40.66M	$65.50M	$67.37M
% Of Pretax Income			36.38%
Net Earnings	-$94.76M	-$223.0M	$120.9M
YoY Change	97.43%	3070.15%	-194.69%
Net Earnings / Revenue	-57.44%	-46.46%	31.44%
Basic Earnings Per Share	-$0.36	-$0.85	$0.46
Diluted Earnings Per Share	-$0.36	-$0.85	$0.46
COMMON SHARES
Basic Shares Outstanding	262.0M shares	262.0M shares
Diluted Shares Outstanding

Balance Sheet

Concept	2014 Q1	2013 Q4	2013 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$13.00M	$17.00M	$12.00M
YoY Change	160.0%	-10.53%
Cash & Equivalents	$12.58M	$17.49M	$11.58M
Short-Term Investments
Other Short-Term Assets	$4.405M	$2.975M	$20.82M
YoY Change	-95.64%	-86.79%
Inventory
Prepaid Expenses
Receivables	$27.25M	$30.61M	$33.02M
Other Receivables	$1.000M	$3.000M	$3.000M
Total Short-Term Assets	$321.9M	$333.6M	$359.5M
YoY Change	65.09%	21.47%
LONG-TERM ASSETS
Property, Plant & Equipment	$6.266B	$5.560B	$4.757B
YoY Change	77.31%	89.27%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$45.43M	$42.58M	$51.91M
YoY Change	-87.49%	30.57%
Total Long-Term Assets	$6.813B	$6.280B	$5.313B
YoY Change	74.78%	87.79%
TOTAL ASSETS
Total Short-Term Assets	$321.9M	$333.6M	$359.5M
Total Long-Term Assets	$6.813B	$6.280B	$5.313B
Total Assets	$7.134B	$6.614B	$5.672B
YoY Change	74.31%	82.76%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$428.9M	$370.6M	$311.1M
YoY Change	60.65%	104.23%
Accrued Expenses	$125.1M	$77.13M	$103.0M
YoY Change	42.16%	31.1%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due		$0.00	$25.00M
YoY Change		-100.0%
Total Short-Term Liabilities	$760.8M	$622.2M	$586.9M
YoY Change	60.85%	65.36%
LONG-TERM LIABILITIES
Long-Term Debt	$2.536B	$2.079B	$2.970B
YoY Change	36.12%	43.98%
Other Long-Term Liabilities	$40.87M	$35.11M	$34.33M
YoY Change	2.17%	6.37%
Total Long-Term Liabilities	$40.87M	$35.11M	$34.33M
YoY Change	-97.85%	6.37%
TOTAL LIABILITIES
Total Short-Term Liabilities	$760.8M	$622.2M	$586.9M
Total Long-Term Liabilities	$40.87M	$35.11M	$34.33M
Total Liabilities	$3.601B	$3.015B	$3.794B
YoY Change	45.98%	55.0%
SHAREHOLDERS EQUITY
Retained Earnings	$99.10M	$193.9M	$416.9M
YoY Change		-8.9%
Common Stock	$2.620M	$2.620M
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$3.533B	$3.599B	$1.878B
YoY Change
Total Liabilities & Shareholders Equity	$7.134B	$6.614B	$5.672B
YoY Change	74.31%	82.76%

Cashflow Statement

Concept	2014 Q1	2013 Q4	2013 Q3
OPERATING ACTIVITIES
Net Income	-$94.76M	-$223.0M	$120.9M
YoY Change	97.43%	3070.15%	-194.69%
Depreciation, Depletion And Amortization	$91.21M	$75.50M	$65.70M
YoY Change	125.96%	105.72%	144.61%
Cash From Operating Activities	$274.3M	$202.8M	$139.5M
YoY Change	148.9%	89.71%	116.61%
INVESTING ACTIVITIES
Capital Expenditures	$731.7M	-$818.3M	-$1.429B
YoY Change	33.12%	-402.51%	79.41%
Acquisitions
YoY Change
Other Investing Activities	$3.807M	$9.600M	$742.3M
YoY Change	-315.33%	-102.19%	92.86%
Cash From Investing Activities	-$735.5M	-$808.7M	-$686.5M
YoY Change	34.25%	380.51%	66.83%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$456.3M	611.9M	547.6M
YoY Change	7.75%	857.59%	52.92%
NET CHANGE
Cash From Operating Activities	$274.3M	202.8M	139.5M
Cash From Investing Activities	-$735.5M	-808.7M	-686.5M
Cash From Financing Activities	$456.3M	611.9M	547.6M
Net Change In Cash	-$4.907M	6.000M	600.0K
YoY Change	-65.4%	140.0%	-94.55%
FREE CASH FLOW
Cash From Operating Activities	$274.3M	$202.8M	$139.5M
Capital Expenditures	$731.7M	-$818.3M	-$1.429B
Free Cash Flow	-$457.4M	$1.021B	$1.568B
YoY Change	4.09%	-724.14%	82.19%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2013	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	15800000	USD
CY2012	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	5200000	USD
CY2011	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	3800000	USD
CY2013	arf	Accounts Receivable Collection Period AccountsReceivableCollectionPeriod	P1M
CY2013Q4	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	11859000	USD
CY2013Q4	us-gaap	Price Risk Derivative Assets At Fair Value PriceRiskDerivativeAssetsAtFairValue	860000000	USD
CY2013	arf	Impairment Of Oil And Gas Properties Leases ImpairmentOfOilAndGasPropertiesLeases	11000000	USD
CY2012	arf	Impairment Of Oil And Gas Properties Leases ImpairmentOfOilAndGasPropertiesLeases	13000000	USD
CY2011	arf	Impairment Of Oil And Gas Properties Leases ImpairmentOfOilAndGasPropertiesLeases	11100000	USD
CY2011	us-gaap	Results Of Operations Depreciation Depletion Amortization And Accretion ResultsOfOperationsDepreciationDepletionAmortizationAndAccretion	164000000	USD
CY2013Q4	us-gaap	Deferred Finance Costs Noncurrent Gross DeferredFinanceCostsNoncurrentGross	28000000	USD
CY2013	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	1039000	USD
CY2012	us-gaap	Results Of Operations Depreciation Depletion Amortization And Accretion ResultsOfOperationsDepreciationDepletionAmortizationAndAccretion	181700000	USD
CY2013	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	item
CY2013	us-gaap	Use Of Estimates UseOfEstimates	<div style="font-size:10.0pt;font-family:Times New Roman;"> <p style="FONT-FAMILY: times;"><font size="2"><b><i>(b)   Use of Estimates</i></b></font></p> <p style="FONT-FAMILY: times;"><font size="2">        The preparation of consolidated financial statements in conformity with generally accepted accounting principles in the United States requires management to make estimates and assumptions that affect the reported assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Changes in facts and circumstances or discovery of new information may result in revised estimates, and actual results could differ from those estimates.</font></p> <p style="FONT-FAMILY: times;"><font size="2">        The Company's consolidated financial statements are based on a number of significant estimates including estimates of gas and oil reserve quantities, which are the basis for the calculation of depreciation, depletion, amortization, present value of cash flows from reserves, and impairment of oil and gas properties. Reserve estimates by their nature are inherently imprecise.</font></p> </div>
CY2013	arf	Maximum Deferment Period Of Significant Costs Pending Determination Of Proved Reserves MaximumDefermentPeriodOfSignificantCostsPendingDeterminationOfProvedReserves	P1Y
CY2013	us-gaap	Results Of Operations Depreciation Depletion Amortization And Accretion ResultsOfOperationsDepreciationDepletionAmortizationAndAccretion	219800000	USD
CY2013Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	30610000	USD
CY2013Q4	us-gaap	Notes And Loans Receivable Net Current NotesAndLoansReceivableNetCurrent	2667000	USD
CY2013Q4	us-gaap	Unproved Oil And Gas Property Successful Effort Method UnprovedOilAndGasPropertySuccessfulEffortMethod	1513136000	USD
CY2013Q4	us-gaap	Proved Oil And Gas Property Successful Effort Method ProvedOilAndGasPropertySuccessfulEffortMethod	3621672000	USD
CY2013Q4	us-gaap	Capitalized Costs Wells And Related Equipment And Facilities CapitalizedCostsWellsAndRelatedEquipmentAndFacilities	584626000	USD
CY2013Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	15757000	USD
CY2013Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	407219000	USD
CY2013Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	370640000	USD
CY2012Q4	us-gaap	Notes Receivable Net NotesReceivableNet	7200000	USD
CY2013Q4	us-gaap	Notes Receivable Net NotesReceivableNet	2700000	USD
CY2012Q4	us-gaap	Notes Payable NotesPayable	1469058000	USD
CY2012Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	181478000	USD
CY2012Q4	us-gaap	Long Term Notes Payable LongTermNotesPayable	1444058000	USD
CY2013Q4	us-gaap	Long Term Notes Payable LongTermNotesPayable	2078999000	USD
CY2013Q4	us-gaap	Notes Payable NotesPayable	2078999000	USD
CY2012Q4	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	10552000	USD
CY2011Q4	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	6715000	USD
CY2013	us-gaap	Accretion Expense AccretionExpense	1065000	USD
CY2012	us-gaap	Accretion Expense AccretionExpense	504000	USD
CY2011	us-gaap	Gain Loss On Sale Of Commodity Contracts GainLossOnSaleOfCommodityContracts	676194000	USD
CY2012	us-gaap	Gain Loss On Sale Of Commodity Contracts GainLossOnSaleOfCommodityContracts	225904000	USD
CY2013	us-gaap	Gain Loss On Sale Of Commodity Contracts GainLossOnSaleOfCommodityContracts	491689000	USD
CY2012	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	15000000	USD
CY2013	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-4000000	USD
CY2011	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	185297000	USD
CY2012	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	121229000	USD
CY2013	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	186210000	USD
CY2011	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35	pure
CY2012	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35	pure
CY2013	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35	pure
CY2011	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	159770000	USD
CY2012	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	121276000	USD
CY2013	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	56708000	USD
CY2011	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	23593000	USD
CY2012	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	4761000	USD
CY2013	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	21429000	USD
CY2011	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-934000	USD
CY2012	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-4872000	USD
CY2013	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-20919000	USD
CY2011	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	2868000	USD
CY2012	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	64000	USD
CY2013	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	1256000	USD
CY2013Q4	us-gaap	Assets Current AssetsCurrent	333564000	USD
CY2013Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	35113000	USD
CY2013Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	5966875000	USD
CY2011	arf	Income Tax Expense Benefit From Continuing And Discontinued Operations IncomeTaxExpenseBenefitFromContinuingAndDiscontinuedOperations	230452000	USD
CY2012	arf	Income Tax Expense Benefit From Continuing And Discontinued Operations IncomeTaxExpenseBenefitFromContinuingAndDiscontinuedOperations	-151324000	USD
CY2013	arf	Income Tax Expense Benefit From Continuing And Discontinued Operations IncomeTaxExpenseBenefitFromContinuingAndDiscontinuedOperations	189459000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	417385000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	5367000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Alternative Minimum Tax DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax	15000000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	5006000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	442758000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	47678000	USD
CY2012Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	395080000	USD
CY2012Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	206937000	USD
CY2013Q4	arf	Deferred Tax Liabilities Property Plant And Equipment Oil And Gas Property DeferredTaxLiabilitiesPropertyPlantAndEquipmentOilAndGasProperty	458812000	USD
CY2012Q4	arf	Deferred Tax Liabilities Property Plant And Equipment Oil And Gas Property DeferredTaxLiabilitiesPropertyPlantAndEquipmentOilAndGasProperty	342455000	USD
CY2012Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	549392000	USD
CY2012Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	154312000	USD
CY2013Q1	us-gaap	Revenues Revenues	61454000	USD
CY2012Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	15000000	USD
CY2013Q4	us-gaap	Contractual Obligation Due In Third Year ContractualObligationDueInThirdYear	374500000	USD
CY2013Q4	us-gaap	Contractual Obligation Due In Fourth Year ContractualObligationDueInFourthYear	354100000	USD
CY2013Q4	us-gaap	Contractual Obligation Due In Fifth Year ContractualObligationDueInFifthYear	349600000	USD
CY2013Q4	us-gaap	Contractual Obligation Due After Fifth Year ContractualObligationDueAfterFifthYear	1853100000	USD
CY2013Q4	us-gaap	Contractual Obligation ContractualObligation	3806000000	USD
CY2012Q4	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	1682297000	USD
CY2013Q4	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	3621672000	USD
CY2012Q4	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	1243237000	USD
CY2013Q4	us-gaap	Contractual Obligation Due In Next Twelve Months ContractualObligationDueInNextTwelveMonths	458100000	USD
CY2013Q4	us-gaap	Contractual Obligation Due In Second Year ContractualObligationDueInSecondYear	416600000	USD
CY2013Q4	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	1513136000	USD
CY2012Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	2925534000	USD
CY2013Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	5134808000	USD
CY2012Q4	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	158210000	USD
CY2013Q4	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	383921000	USD
CY2012Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	2767324000	USD
CY2013Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	4750887000	USD
CY2011	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	105405000	USD
CY2012	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	10254000	USD
CY2013	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	15300000	USD
CY2011	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	195131000	USD
CY2012	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	687403000	USD
CY2012Q4	us-gaap	Revenues Revenues	235090000	USD
CY2012Q4	us-gaap	Operating Expenses OperatingExpenses	111077000	USD
CY2012Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	124013000	USD
CY2013	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	440825000	USD
CY2011	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	432147000	USD
CY2012	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	678276000	USD
CY2013	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	780583000	USD
CY2011	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	828246000	USD
CY2012	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	1534007000	USD
CY2013	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	2072090000	USD
CY2011	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	391994000	USD
CY2012	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	390378000	USD
CY2013	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	821445000	USD
CY2011	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	136635000	USD
CY2012	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	185505000	USD
CY2013	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	278348000	USD
CY2011	us-gaap	Results Of Operations Exploration Expense ResultsOfOperationsExplorationExpense	9876000	USD
CY2012	us-gaap	Results Of Operations Exploration Expense ResultsOfOperationsExplorationExpense	15339000	USD
CY2013	us-gaap	Results Of Operations Exploration Expense ResultsOfOperationsExplorationExpense	22272000	USD
CY2011	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	164011000	USD
CY2012	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	181664000	USD
CY2013	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	219830000	USD
CY2011	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	11051000	USD
CY2012	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	13032000	USD
CY2013	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	10928000	USD
CY2011	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	70421000	USD
CY2012	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	-5162000	USD
CY2013	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	290067000	USD
CY2011	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	26056000	USD
CY2012	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	-2008000	USD
CY2013	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	110805000	USD
CY2011	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	44365000	USD
CY2012	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	-3154000	USD
CY2013	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	179262000	USD
CY2013	arf	Period Of Average Pricing To Estimate Proved Reserves PeriodOfAveragePricingToEstimateProvedReserves	P12M
CY2013	arf	Proved Undeveloped Reserves Drilling Scheduled Period ProvedUndevelopedReservesDrillingScheduledPeriod	P5Y
CY2013	arf	Decrease In Proved Reserves Due To Downward Price Revisions DecreaseInProvedReservesDueToDownwardPriceRevisions	692000000
CY2013Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	77126000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Cash Inflows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureCashInflows	20046000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Cash Inflows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureCashInflows	12151000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Cash Inflows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureCashInflows	30113000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Production Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureProductionCosts1	-3491000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Production Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureProductionCosts1	-1660000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Production Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureProductionCosts1	-5967000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Development Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureDevelopmentCosts1	-5085000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Development Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureDevelopmentCosts1	-3270000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Development Costs1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureDevelopmentCosts1	-5349000000	USD
CY2011	arf	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows Before Income Tax Expense DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlowsBeforeIncomeTaxExpense	11470000000	USD
CY2012	arf	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows Before Income Tax Expense DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlowsBeforeIncomeTaxExpense	7221000000	USD
CY2013	arf	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows Before Income Tax Expense DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlowsBeforeIncomeTaxExpense	18797000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Income Tax Expense1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureIncomeTaxExpense1	-3287000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Income Tax Expense1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureIncomeTaxExpense1	-1603000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Income Tax Expense1 DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureIncomeTaxExpense1	-5308000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlows	8183000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlows	5618000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Future Net Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesFutureNetCashFlows	13489000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves10 Percent Annual Discount For Estimated Timing Of Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves10PercentAnnualDiscountForEstimatedTimingOfCashFlows	5713000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves10 Percent Annual Discount For Estimated Timing Of Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves10PercentAnnualDiscountForEstimatedTimingOfCashFlows	4017000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves10 Percent Annual Discount For Estimated Timing Of Cash Flows DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves10PercentAnnualDiscountForEstimatedTimingOfCashFlows	8979000000	USD
CY2011	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Standardized Measure DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesStandardizedMeasure	2470000000	USD
CY2012	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Standardized Measure DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesStandardizedMeasure	1601000000	USD
CY2013	us-gaap	Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves Standardized Measure DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesStandardizedMeasure	4510000000	USD
CY2011	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	255000000	USD
CY2011	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	215000000	USD
CY2013Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	646000	USD
CY2011	us-gaap	Previously Estimated Development Costs Incurred During Period PreviouslyEstimatedDevelopmentCostsIncurredDuringPeriod	-247000000	USD
CY2011	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-106000000	USD
CY2011	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	1684000000	USD
CY2013Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	193860000	USD
CY2011	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Period Increase Decrease StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease	1373000000	USD
CY2011	arf	Decrease In Proved Reserves Due To Downward Price Revisions DecreaseInProvedReservesDueToDownwardPriceRevisions	6000000
CY2011	arf	Decrease In Proved Reserves Due To Performance Revisions DecreaseInProvedReservesDueToPerformanceRevisions	346000000
CY2011	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	-182000000	USD
CY2011	us-gaap	Accretion Of Discount AccretionOfDiscount	147000000	USD
CY2011	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	-605000000	USD
CY2011	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Other StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther	177000000	USD
CY2012	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	147000000	USD
CY2012	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	-1631000000	USD
CY2012	us-gaap	Previously Estimated Development Costs Incurred During Period PreviouslyEstimatedDevelopmentCostsIncurredDuringPeriod	-296000000	USD
CY2012	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-92000000	USD
CY2012	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	813000000	USD
CY2011	us-gaap	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	51000000	USD
CY2012	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	88000000	USD
CY2012	us-gaap	Accretion Of Discount AccretionOfDiscount	322000000	USD
CY2012	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	653000000	USD
CY2012	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Other StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther	106000000	USD
CY2012	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Period Increase Decrease StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease	-869000000	USD
CY2013	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	761000000	USD
CY2013	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	1061000000	USD
CY2013	us-gaap	Previously Estimated Development Costs Incurred During Period PreviouslyEstimatedDevelopmentCostsIncurredDuringPeriod	-384000000	USD
CY2013	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-181000000	USD
CY2013	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	3441000000	USD
CY2013	us-gaap	Natural Gas Production Revenue NaturalGasProductionRevenue	689198000	USD
CY2013	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	-270000000	USD
CY2013	us-gaap	Accretion Of Discount AccretionOfDiscount	192000000	USD
CY2013	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	-1165000000	USD
CY2013	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Other StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther	206000000	USD
CY2013	us-gaap	Standardized Measure Of Discounted Future Net Cash Flow Of Proved Oil And Gas Reserves Period Increase Decrease StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease	2909000000	USD
CY2010Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1097000000	USD
CY2011Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	2470000000	USD
CY2012Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1601000000	USD
CY2013Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	4510000000	USD
CY2013Q4	us-gaap	Assets Assets	6613581000	USD
CY2013Q4	us-gaap	Liabilities Liabilities	3014921000	USD
CY2013Q4	us-gaap	Stockholders Equity StockholdersEquity	3598660000	USD
CY2012Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	18989000	USD
CY2012Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	21296000	USD
CY2011	arf	Derivative Instruments Gain Loss Recognized On Commodity Derivative Instrument In Income Net DerivativeInstrumentsGainLossRecognizedOnCommodityDerivativeInstrumentInIncomeNet	496064000	USD
CY2012Q4	us-gaap	Notes And Loans Receivable Net Current NotesAndLoansReceivableNetCurrent	4555000	USD
CY2012Q4	us-gaap	Accrued Fees And Other Revenue Receivable AccruedFeesAndOtherRevenueReceivable	46669000	USD
CY2012Q4	us-gaap	Derivative Assets Current DerivativeAssetsCurrent	160579000	USD
CY2012Q4	us-gaap	Other Assets Current OtherAssetsCurrent	22518000	USD
CY2012Q4	us-gaap	Assets Current AssetsCurrent	274606000	USD
CY2013Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	6613581000	USD
CY2012Q4	us-gaap	Unproved Oil And Gas Property Successful Effort Method UnprovedOilAndGasPropertySuccessfulEffortMethod	1243237000	USD
CY2012Q4	us-gaap	Proved Oil And Gas Property Successful Effort Method ProvedOilAndGasPropertySuccessfulEffortMethod	1682297000	USD
CY2012Q4	us-gaap	Capitalized Costs Wells And Related Equipment And Facilities CapitalizedCostsWellsAndRelatedEquipmentAndFacilities	168930000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	9517000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	3110816000	USD
CY2012Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	173343000	USD
CY2012Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	2937473000	USD
CY2012Q4	us-gaap	Derivative Assets Noncurrent DerivativeAssetsNoncurrent	371436000	USD
CY2012Q4	us-gaap	Notes And Loans Receivable Net Noncurrent NotesAndLoansReceivableNetNoncurrent	2667000	USD
CY2012Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	32611000	USD
CY2012Q4	us-gaap	Assets Assets	3618793000	USD
CY2011	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	185297000	USD
CY2012Q4	arf	Revenue Distributions Payable Current RevenueDistributionsPayableCurrent	46037000	USD
CY2012Q4	us-gaap	Notes Payable Current NotesPayableCurrent	25000000	USD
CY2012Q4	us-gaap	Deferred Tax Liabilities Current DeferredTaxLiabilitiesCurrent	62620000	USD
CY2012Q4	us-gaap	Liabilities Current LiabilitiesCurrent	376296000	USD
CY2012Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	91692000	USD
CY2012Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	33010000	USD
CY2012Q4	us-gaap	Liabilities Liabilities	1945056000	USD
CY2012Q4	arf	Stockholders Equity Excluding Accumulated Deficit StockholdersEquityExcludingAccumulatedDeficit	1460947000	USD
CY2012Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	212790000	USD
CY2012Q4	us-gaap	Stockholders Equity StockholdersEquity	1673737000	USD
CY2012Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	3618793000	USD
CY2011	us-gaap	Natural Gas Production Revenue NaturalGasProductionRevenue	195116000	USD
CY2012	us-gaap	Natural Gas Production Revenue NaturalGasProductionRevenue	259743000	USD
CY2012	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-97510000	USD
CY2012	arf	Natural Gas Liquids Revenues NaturalGasLiquidsRevenues	3719000	USD
CY2011	arf	Oil Revenue OilRevenue	173000	USD
CY2012	arf	Oil Revenue OilRevenue	1520000	USD
CY2012	arf	Derivative Instruments Gain Loss Recognized On Commodity Derivative Instrument In Income Net DerivativeInstrumentsGainLossRecognizedOnCommodityDerivativeInstrumentInIncomeNet	179546000	USD
CY2012	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	291190000	USD
CY2011	us-gaap	Revenues Revenues	691353000	USD
CY2012	us-gaap	Revenues Revenues	735718000	USD
CY2013	us-gaap	Revenues Revenues	1313134000	USD
CY2013	us-gaap	Operating Expenses OperatingExpenses	971927000	USD
CY2012Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	84845000	USD
CY2012Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-91880000	USD
CY2013	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-24187000	USD
CY2013	arf	Natural Gas Liquids Revenues NaturalGasLiquidsRevenues	111663000	USD
CY2011	us-gaap	Oil And Gas Production Expense OilAndGasProductionExpense	4608000	USD
CY2012	us-gaap	Oil And Gas Production Expense OilAndGasProductionExpense	6243000	USD
CY2011	us-gaap	Gas Gathering Transportation Marketing And Processing Costs GasGatheringTransportationMarketingAndProcessingCosts	37315000	USD
CY2012	us-gaap	Gas Gathering Transportation Marketing And Processing Costs GasGatheringTransportationMarketingAndProcessingCosts	91094000	USD
CY2012	arf	Payments Of Financing Costs And Gains Losses On Extinguishment Of Debt PaymentsOfFinancingCostsAndGainsLossesOnExtinguishmentOfDebt	5926000	USD
CY2011	arf	Payments Of Financing Costs And Gains Losses On Extinguishment Of Debt PaymentsOfFinancingCostsAndGainsLossesOnExtinguishmentOfDebt	6691000	USD
CY2013	us-gaap	Oil And Gas Production Expense OilAndGasProductionExpense	9439000	USD
CY2011	us-gaap	Exploration Expense ExplorationExpense	4034000	USD
CY2012	us-gaap	Exploration Expense ExplorationExpense	14675000	USD
CY2011	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	4664000	USD
CY2013	dei	Entity Registrant Name EntityRegistrantName	ANTERO RESOURCES Corp
CY2011	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	55716000	USD
CY2012	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	102026000	USD
CY2011	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	76000	USD
CY2012	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	101000	USD
CY2011	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	33342000	USD
CY2012	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	45284000	USD
CY2011	us-gaap	Operating Expenses OperatingExpenses	160370000	USD
CY2012	us-gaap	Operating Expenses OperatingExpenses	291703000	USD
CY2011	us-gaap	Operating Income Loss OperatingIncomeLoss	530983000	USD
CY2012	us-gaap	Operating Income Loss OperatingIncomeLoss	444015000	USD
CY2011	us-gaap	Interest Expense InterestExpense	74404000	USD
CY2012	us-gaap	Interest Expense InterestExpense	97510000	USD
CY2011	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	456485000	USD
CY2012	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	346505000	USD
CY2011	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	271188000	USD
CY2012	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	225276000	USD
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	121490000	USD
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-510345000	USD
CY2011	us-gaap	Net Income Loss NetIncomeLoss	392678000	USD
CY2012	us-gaap	Net Income Loss NetIncomeLoss	-285069000	USD
CY2013	dei	Entity Central Index Key EntityCentralIndexKey	0001433270
CY2013	dei	Document Type DocumentType	10-K
CY2013	us-gaap	Profit Loss ProfitLoss	-18930000	USD
CY2013	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	534707000	USD
CY2013	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2673592000	USD
CY2013	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2137383000	USD
CY2013	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-1502000	USD
CY2013	dei	Document Period End Date DocumentPeriodEndDate	2013-12-31
CY2013	dei	Amendment Flag AmendmentFlag	false
CY2013	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2013	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2013	dei	Entity Filer Category EntityFilerCategory	Non-accelerated Filer
CY2011	us-gaap	Profit Loss ProfitLoss	392678000	USD
CY2012	us-gaap	Profit Loss ProfitLoss	-285069000	USD
CY2011	arf	Depletion Depreciation And Amortization DepletionDepreciationAndAmortization	55792000	USD
CY2012	arf	Depletion Depreciation And Amortization DepletionDepreciationAndAmortization	102127000	USD
CY2014Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	262049659	shares
CY2012	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	12070000	USD
CY2011	us-gaap	Unrealized Gain Loss On Derivatives And Commodity Contracts UnrealizedGainLossOnDerivativesAndCommodityContracts	495970000	USD
CY2012	us-gaap	Unrealized Gain Loss On Derivatives And Commodity Contracts UnrealizedGainLossOnDerivativesAndCommodityContracts	179546000	USD
CY2011	arf	Proceeds From Settled Derivative Instruments Operating Activities ProceedsFromSettledDerivativeInstrumentsOperatingActivities	45638000	USD
CY2012	arf	Proceeds From Settled Derivative Instruments Operating Activities ProceedsFromSettledDerivativeInstrumentsOperatingActivities	178491000	USD
CY2013	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2013	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2013
CY2011	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-8700000	USD
CY2012	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	291190000	USD
CY2012	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	-795945000	USD
CY2011	arf	Depletion Depreciation Amortization Impairment Of Oil And Gas Properties And Dryhole Expense Discontinued Operations DepletionDepreciationAmortizationImpairmentOfOilAndGasPropertiesAndDryholeExpenseDiscontinuedOperations	126041000	USD
CY2012	arf	Depletion Depreciation Amortization Impairment Of Oil And Gas Properties And Dryhole Expense Discontinued Operations DepletionDepreciationAmortizationImpairmentOfOilAndGasPropertiesAndDryholeExpenseDiscontinuedOperations	90096000	USD
CY2011	arf	Proceeds From Settled Derivative Instruments Operating Activities Discontinued Operations ProceedsFromSettledDerivativeInstrumentsOperatingActivitiesDiscontinuedOperations	66654000	USD
CY2012	arf	Proceeds From Settled Derivative Instruments Operating Activities Discontinued Operations ProceedsFromSettledDerivativeInstrumentsOperatingActivitiesDiscontinuedOperations	92166000	USD
CY2012	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	15646000	USD
CY2011	arf	Deferred Income Tax Expense Benefit Discontinued Operations DeferredIncomeTaxExpenseBenefitDiscontinuedOperations	45155000	USD
CY2012	arf	Deferred Income Tax Expense Benefit Discontinued Operations DeferredIncomeTaxExpenseBenefitDiscontinuedOperations	-272553000	USD
CY2011	us-gaap	Other Noncash Expense OtherNoncashExpense	3479000	USD
CY2012	us-gaap	Other Noncash Expense OtherNoncashExpense	4960000	USD
CY2011	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-3854000	USD
CY2012	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-5511000	USD
CY2011	arf	Increase Decrease In Accrued Revenue IncreaseDecreaseInAccruedRevenue	11118000	USD
CY2012	arf	Increase Decrease In Accrued Revenue IncreaseDecreaseInAccruedRevenue	10683000	USD
CY2011	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	4528000	USD
CY2012	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	8882000	USD
CY2011	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-1875000	USD
CY2012	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-2117000	USD
CY2011	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	17124000	USD
CY2012	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	14790000	USD
CY2011	arf	Increase Decrease In Revenue Distributions Payable IncreaseDecreaseInRevenueDistributionsPayable	4852000	USD
CY2012	arf	Increase Decrease In Revenue Distributions Payable IncreaseDecreaseInRevenueDistributionsPayable	11268000	USD
CY2012	us-gaap	Increase Decrease In Other Current Assets And Liabilities Net IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet	-15000000	USD
CY2011	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	266307000	USD
CY2012	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	332255000	USD
CY2011	arf	Payments To Acquired Proved Property PaymentsToAcquiredProvedProperty	105405000	USD
CY2012	arf	Payments To Acquired Proved Property PaymentsToAcquiredProvedProperty	10254000	USD
CY2011	us-gaap	Payments To Acquire Oil And Gas Property PaymentsToAcquireOilAndGasProperty	195131000	USD
CY2012	us-gaap	Payments To Acquire Oil And Gas Property PaymentsToAcquireOilAndGasProperty	687403000	USD
CY2011	us-gaap	Payments To Acquire Oil And Gas Equipment PaymentsToAcquireOilAndGasEquipment	72837000	USD
CY2012	us-gaap	Payments To Acquire Oil And Gas Equipment PaymentsToAcquireOilAndGasEquipment	142294000	USD
CY2011	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	2339000	USD
CY2012	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	3447000	USD
CY2011	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	15379000	USD
CY2012	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	1217876000	USD
CY2011	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-901249000	USD
CY2012	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-463491000	USD
CY2011	us-gaap	Proceeds From Issuance Of Unsecured Debt ProceedsFromIssuanceOfUnsecuredDebt	400000000	USD
CY2012	us-gaap	Proceeds From Issuance Of Unsecured Debt ProceedsFromIssuanceOfUnsecuredDebt	300000000	USD
CY2011	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	265000000	USD
CY2012	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	-148000000	USD
CY2011	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-153000	USD
CY2012	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	808000	USD
CY2011	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	629297000	USD
CY2012	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	146882000	USD
CY2011	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-5645000	USD
CY2011	us-gaap	Interest Paid InterestPaid	59107000	USD
CY2012	us-gaap	Interest Paid InterestPaid	90122000	USD
CY2011	arf	Increase Decrease In Capital Expenditures Incurred But Not Yet Paid IncreaseDecreaseInCapitalExpendituresIncurredButNotYetPaid	26465000	USD
CY2012	arf	Increase Decrease In Capital Expenditures Incurred But Not Yet Paid IncreaseDecreaseInCapitalExpendituresIncurredButNotYetPaid	72881000	USD
CY2010Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	8988000	USD
CY2011Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	3343000	USD
CY2013Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	3402180000	USD
CY2013Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2012Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2013Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2012Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2012Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	58829000	USD
CY2013Q4	us-gaap	Common Stock Value CommonStockValue	2620000	USD
CY2013	arf	Oil Revenue OilRevenue	20584000	USD
CY2013Q4	us-gaap	Preferred Stock Value PreferredStockValue		USD
CY2013Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	262049659	shares
CY2013Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	262049659	shares
CY2012Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	262049659	shares
CY2012Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	262049659	shares
CY2013Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2012Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2013	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	26803000	USD
CY2013Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	50000000	shares
CY2012Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	50000000	shares
CY2013Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2012Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2013Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1251000	USD
CY2011	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-74498000	USD
CY2011	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Discontinued Operation During Phase Out Period DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod	45155000	USD
CY2012	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Discontinued Operation During Phase Out Period DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod	-272533000	USD
CY2013	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Discontinued Operation During Phase Out Period DiscontinuedOperationTaxEffectOfIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriod	3249000	USD
CY2010Q4	us-gaap	Stockholders Equity StockholdersEquity	1594987000	USD
CY2011Q4	us-gaap	Stockholders Equity StockholdersEquity	1958806000	USD
CY2013	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	1578573000	USD
CY2011	us-gaap	Partners Capital Account Distributions PartnersCapitalAccountDistributions	28859000	USD
CY2013	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	37674659	shares
CY2011	us-gaap	Increase Decrease In Notes Receivables IncreaseDecreaseInNotesReceivables	10111000	USD
CY2012	us-gaap	Increase Decrease In Notes Receivables IncreaseDecreaseInNotesReceivables	-4889000	USD
CY2011	us-gaap	Payments Of Capital Distribution PaymentsOfCapitalDistribution	28859000	USD
CY2012	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	106229000	USD
CY2011	arf	Unrealized Losses On Derivative Instruments Net Discontinued Operations UnrealizedLossesOnDerivativeInstrumentsNetDiscontinuedOperations	-180130000	USD
CY2012	arf	Unrealized Losses On Derivative Instruments Net Discontinued Operations UnrealizedLossesOnDerivativeInstrumentsNetDiscontinuedOperations	-46358000	USD
CY2011	us-gaap	Payments To Explore And Develop Oil And Gas Properties PaymentsToExploreAndDevelopOilAndGasProperties	527710000	USD
CY2012	us-gaap	Payments To Explore And Develop Oil And Gas Properties PaymentsToExploreAndDevelopOilAndGasProperties	836350000	USD
CY2011	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	3095000	USD
CY2012	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	3707000	USD
CY2011	us-gaap	Gain Loss On Sales Of Assets And Asset Impairment Charges GainLossOnSalesOfAssetsAndAssetImpairmentCharges	-8700000	USD
CY2012Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-444850000	USD
CY2012Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-13791000	USD
CY2012Q1	us-gaap	Net Income Loss NetIncomeLoss	327731000	USD
CY2012Q2	us-gaap	Net Income Loss NetIncomeLoss	-478087000	USD
CY2013	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-19543000	USD
CY2013	us-gaap	Payments To Acquire Oil And Gas Property PaymentsToAcquireOilAndGasProperty	440825000	USD
CY2012Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-33237000	USD
CY2012Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-113887000	USD
CY2012Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	40176000	USD
CY2013	arf	Increase Decrease In Accrued Revenue IncreaseDecreaseInAccruedRevenue	50156000	USD
CY2013	arf	Increase Decrease In Revenue Distributions Payable IncreaseDecreaseInRevenueDistributionsPayable	50552000	USD
CY2013	us-gaap	Increase Decrease In Other Current Assets And Liabilities Net IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet	-3447000	USD
CY2012	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	9440000	USD
CY2012	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	6107000	USD
CY2013Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	449961000	USD
CY2013	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	491689000	USD
CY2011	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	676100000	USD
CY2012	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	225904000	USD
CY2013	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	190210000	USD
CY2011	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	45155000	USD
CY2012	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	-272553000	USD
CY2013	us-gaap	Discontinued Operation Tax Effect Of Discontinued Operation DiscontinuedOperationTaxEffectOfDiscontinuedOperation	3249000	USD
CY2013Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	11000000	USD
CY2013Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	500000	USD
CY2013Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Alternative Minimum Tax DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax	11000000	USD
CY2013Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	5373000	USD
CY2012Q4	us-gaap	Net Income Loss NetIncomeLoss	-7035000	USD
CY2013	us-gaap	Adjustments To Additional Paid In Capital Stock Issued Issuance Costs AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	79112000	USD
CY2013Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	466334000	USD
CY2012Q1	us-gaap	Revenues Revenues	553741000	USD
CY2012Q2	us-gaap	Revenues Revenues	38925000	USD
CY2012Q3	us-gaap	Revenues Revenues	-92038000	USD
CY2012Q1	us-gaap	Operating Expenses OperatingExpenses	43405000	USD
CY2012Q2	us-gaap	Operating Expenses OperatingExpenses	62381000	USD
CY2012Q3	us-gaap	Operating Expenses OperatingExpenses	74840000	USD
CY2012Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	510336000	USD
CY2012Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	-23456000	USD
CY2012Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	-166878000	USD
CY2012Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	287555000	USD
CY2012Q3	us-gaap	Net Income Loss NetIncomeLoss	-127678000	USD
CY2012Q4	arf	Capitalized Costs Fresh Water Distribution Systems CapitalizedCostsFreshWaterDistributionSystems	6835000	USD
CY2012	us-gaap	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	1277000000	USD
CY2013	us-gaap	Gas Gathering Transportation Marketing And Processing Costs GasGatheringTransportationMarketingAndProcessingCosts	218428000	USD
CY2013	us-gaap	Exploration Expense ExplorationExpense	22272000	USD
CY2013	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	1065000	USD
CY2013	arf	Deferred Income Tax Expense Benefit Discontinued Operations DeferredIncomeTaxExpenseBenefitDiscontinuedOperations	3249000	USD
CY2013	us-gaap	Other Noncash Expense OtherNoncashExpense	1173000	USD
CY2013	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	9314000	USD
CY2013	arf	Payments To Acquired Proved Property PaymentsToAcquiredProvedProperty	15300000	USD
CY2013Q4	arf	Revenue Distributions Payable Current RevenueDistributionsPayableCurrent	96589000	USD
CY2013Q4	us-gaap	Deferred Tax Liabilities Current DeferredTaxLiabilitiesCurrent	69191000	USD
CY2013	us-gaap	Payments To Explore And Develop Oil And Gas Properties PaymentsToExploreAndDevelopOilAndGasProperties	1615965000	USD
CY2013	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	6240000	USD
CY2012	arf	Decrease In Proved Reserves Due To Downward Price Revisions DecreaseInProvedReservesDueToDownwardPriceRevisions	102000000
CY2013	us-gaap	Increase Decrease In Notes Receivables IncreaseDecreaseInNotesReceivables	-4555000	USD
CY2013	arf	Payments Of Financing Costs And Gains Losses On Extinguishment Of Debt PaymentsOfFinancingCostsAndGainsLossesOnExtinguishmentOfDebt	53940000	USD
CY2012	arf	Increase In Proved Reserves Due To Performance Revisions IncreaseInProvedReservesDueToPerformanceRevisions	324000000
CY2013	us-gaap	Interest Paid InterestPaid	117832000	USD
CY2013	arf	Increase Decrease In Capital Expenditures Incurred But Not Yet Paid IncreaseDecreaseInCapitalExpendituresIncurredButNotYetPaid	188123000	USD
CY2013	arf	Period Of Unweighted First Day Of Month Average Prices Applied To Compute Future Cash Inflows PeriodOfUnweightedFirstDayOfMonthAveragePricesAppliedToComputeFutureCashInflows	P12M
CY2013	us-gaap	Revenue Recognition Sales Of Goods RevenueRecognitionSalesOfGoods	<div style="font-size:10.0pt;font-family:Times New Roman;"> <p style="FONT-FAMILY: times;"><font size="2"><b><i>(m)  Natural Gas, NGL and Oil Revenues</i></b></font></p> <p style="FONT-FAMILY: times;"><font size="2">        Sales of natural gas, NGLs, and crude oil are recognized when the products are delivered to the purchaser and title transfers to the purchaser. Payment is generally received one month after the sale has occurred. Variances between estimated sales and actual amounts received are recorded in the month payment is received and are not material. The Company recognizes natural gas revenues based on its entitlement share of natural gas that is produced based on its working interests in the properties. The Company records a revenue distribution payable to the extent it receives more than its proportionate share natural gas revenues. At December 31, 2012 and 2013, the Company had no significant imbalance positions.</font></p> </div>
CY2013	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="font-size:10.0pt;font-family:Times New Roman;"> <p style="FONT-FAMILY: times;"><font size="2"><b><i>(n)   Concentrations of Credit Risk</i></b></font></p> <p style="FONT-FAMILY: times;"><font size="2">        The Company's revenues are derived principally from uncollateralized sales to purchasers in the oil and gas industry. The concentration of credit risk in a single industry affects the Company's overall exposure to credit risk because purchasers may be similarly affected by changes in economic and other conditions. The Company has not experienced significant credit losses on its receivables.</font></p> <p style="FONT-FAMILY: times;"><font size="2">        The Company's sales to major customers (purchases in excess of 10% of total sales) for the years ended December 31, 2011, 2012, and 2013 are as follows (including sales in discontinued operations):</font></p> <div style="POSITION: relative; PADDING-BOTTOM: 0pt; PADDING-LEFT: 0pt; WIDTH: 70%; PADDING-RIGHT: 0pt; MARGIN-LEFT: 15%; PADDING-TOP: 0pt;"> <p style="FONT-FAMILY: times;"><font size="2"><!-- COMMAND=ADD_TABLEWIDTH,"100%" --></font></p> <!-- User-specified TAGGED TABLE --> <div align="center"> <table border="0" cellspacing="0" cellpadding="0" width="100%" style="text-align:left;"> <tr style="padding:0;"><!-- TABLE COLUMN WIDTHS SET --> <td style="FONT-FAMILY: times;" align="left"></td> <td style="FONT-FAMILY: times;" width="12"></td> <td style="FONT-FAMILY: times;" width="7" align="right"></td> <td style="FONT-FAMILY: times;" width="25"></td> <td style="FONT-FAMILY: times;" width="12"></td> <td style="FONT-FAMILY: times;" width="7" align="right"></td> <td style="FONT-FAMILY: times;" width="25"></td> <td style="FONT-FAMILY: times;" width="12"></td> <td style="FONT-FAMILY: times;" width="7" align="right"></td> <td style="FONT-FAMILY: times;" width="25"></td> <td style="FONT-FAMILY: times;" width="12"></td><!-- TABLE COLUMN WIDTHS END --></tr> <tr style="padding:0;" valign="bottom"> <th style="FONT-FAMILY: times;" align="left"><font size="2"> </font><br /></th> <th style="FONT-FAMILY: times;"><font size="1"> </font></th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times;" colspan="2" align="center"><font size="1"><b>2011</b></font></th> <th style="FONT-FAMILY: times;"><font size="1"> </font></th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times;" colspan="2" align="center"><font size="1"><b>2012</b></font></th> <th style="FONT-FAMILY: times;"><font size="1"> </font></th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times;" colspan="2" align="center"><font size="1"><b>2013</b></font></th> <th style="FONT-FAMILY: times;"><font size="1"> </font></th></tr> <tr style="padding:0;" valign="top" bgcolor="#CCEEFF"> <td style="FONT-FAMILY: times;" valign="bottom"> <p style="TEXT-INDENT: -10pt; FONT-FAMILY: times; MARGIN-LEFT: 10pt;"><font size="2">Company A</font></p></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">28</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">23</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">30</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td></tr> <tr style="padding:0;" valign="top" bgcolor="white"> <td style="FONT-FAMILY: times;" valign="bottom"> <p style="TEXT-INDENT: -10pt; FONT-FAMILY: times; MARGIN-LEFT: 10pt;"><font size="2">Company B</font></p></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">17</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">13</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">14</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td></tr> <tr style="padding:0;" valign="top" bgcolor="#CCEEFF"> <td style="FONT-FAMILY: times;" valign="bottom"> <p style="TEXT-INDENT: -10pt; FONT-FAMILY: times; MARGIN-LEFT: 10pt;"><font size="2">Company C</font></p></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">12</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">10</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">8</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td></tr> <tr style="padding:0;" valign="top" bgcolor="white"> <td style="FONT-FAMILY: times;" valign="bottom"> <p style="TEXT-INDENT: -10pt; FONT-FAMILY: times; MARGIN-LEFT: 10pt;"><font size="2">All others</font></p></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">43</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">54</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">48</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td></tr> <tr style="padding:0; FONT-SIZE: 1.5pt;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0pt;" --> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td></tr> <tr style="padding:0;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"><font size="2"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0.1pt;" --></font></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td></tr> <tr style="padding:0;" valign="top" bgcolor="#CCEEFF"> <td style="FONT-FAMILY: times;" valign="bottom"> <p style="TEXT-INDENT: -10pt; FONT-FAMILY: times; MARGIN-LEFT: 10pt;"> </p></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">100</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">100</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2"> </font></td> <td style="FONT-FAMILY: times;" valign="bottom" align="right"><font size="2">100</font></td> <td style="FONT-FAMILY: times;" valign="bottom"><font size="2">%</font></td></tr> <tr style="padding:0; FONT-SIZE: 1.5pt;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0pt;" --> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td></tr> <tr style="padding:0;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"><font size="2"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0.1pt;" --></font></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.1pt; FONT-FAMILY: times;" valign="bottom"></td></tr> <tr style="padding:0;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"><font size="2"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0.75pt;" --></font></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom" align="right"></td> <td style="LINE-HEIGHT: 0.75pt; FONT-FAMILY: times;" valign="bottom"></td></tr> <tr style="padding:0; FONT-SIZE: 1.5pt;" valign="top" bgcolor="#ffffff"> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"><!-- COMMAND=ADD_ROWSHADECOLOR,"#FFFFFF" --><!-- COMMAND=ADD_GUTTERGRID,"line-height:0pt;" --> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1pt solid; LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom" colspan="2" align="right"> </td> <td style="LINE-HEIGHT: 0pt; FONT-FAMILY: times;" valign="bottom"> </td></tr></table></div> <!-- end of user-specified TAGGED TABLE --></div> <p style="FONT-FAMILY: times;"><font size="2">        Although a substantial portion of production is purchased by these major customers, we do not believe the loss of any one or several customers would have a material adverse effect on our business, as other customers or markets would be accessible to us.</font></p> <p style="FONT-FAMILY: times;"><font size="2">        The Company is also exposed to credit risk on its commodity derivative portfolio. Any default by the counterparties to these derivative contracts when they become due would have a material adverse effect on our financial condition and results of operations. The fair value of our commodity derivative contracts of approximately $860 million at December 31, 2013 includes the following values by bank counterparty: BNP Paribas—$197 million; Credit Suisse—$190 million; Barclays—$147 million; Wells Fargo—$140 million; JP Morgan—$134 million; Citigroup—$34 million; Deutsche Bank—$15 million; and Toronto Dominion Bank—$3 million. The estimated fair value of our commodity derivative assets has been risk adjusted using a discount rate based upon the respective published credit default swap rates at December 31, 2013 for each of the European and American banks. We believe that all of these institutions currently are acceptable credit risks.</font></p> <p style="FONT-FAMILY: times;"><font size="2">        The Company, at times, may have cash in banks in excess of federally insured amounts.</font></p> </div>
CY2013Q4	us-gaap	Proved Undeveloped Reserve Boe1 ProvedUndevelopedReserveBOE1	5610000000
CY2012	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	158074000	USD
CY2013	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions	4000000	USD
CY2013	arf	Impairment Of Oil And Gas Properties Proved ImpairmentOfOilAndGasPropertiesProved	0	USD
CY2012	arf	Impairment Of Oil And Gas Properties Proved ImpairmentOfOilAndGasPropertiesProved	0	USD
CY2011	arf	Impairment Of Oil And Gas Properties Proved ImpairmentOfOilAndGasPropertiesProved	0	USD
CY2013	arf	Impairment Of Long Lived Assets Other Than Properties Oil And Gas Properties ImpairmentOfLongLivedAssetsOtherThanPropertiesOilAndGasProperties	0	USD
CY2013	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	835382000	USD
CY2010Q4	arf	Proved Developed And Undeveloped Reserves Net Energy ProvedDevelopedAndUndevelopedReservesNetEnergy	3231000000
CY2011Q4	arf	Proved Developed And Undeveloped Reserves Net Energy ProvedDevelopedAndUndevelopedReservesNetEnergy	5017000000
CY2012Q4	arf	Proved Developed And Undeveloped Reserves Net Energy ProvedDevelopedAndUndevelopedReservesNetEnergy	4929000000
CY2013Q4	arf	Proved Developed And Undeveloped Reserves Net Energy ProvedDevelopedAndUndevelopedReservesNetEnergy	7632000000
CY2011	arf	Proved Developed And Undeveloped Reserves Extensions Discoveries And Additions Energy ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditionsEnergy	1982000000
CY2011	arf	Proved Developed And Undeveloped Reserves Purchases Of Minerals In Place Energy ProvedDevelopedAndUndevelopedReservesPurchasesOfMineralsInPlaceEnergy	66000000
CY2012	arf	Proved Developed And Undeveloped Reserves Revisions Of Previous Estimates Increase Decrease Energy ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecreaseEnergy	222000000
CY2012	arf	Proved Developed And Undeveloped Reserves Extensions Discoveries And Additions Energy ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditionsEnergy	1951000000
CY2013	arf	Proved Developed And Undeveloped Reserves Revisions Of Previous Estimates Increase Decrease Energy ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecreaseEnergy	-788000000
CY2013	arf	Proved Developed And Undeveloped Reserves Extensions Discoveries And Additions Energy ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditionsEnergy	3682000000
CY2013	arf	Proved Developed And Undeveloped Reserves Production Energy ProvedDevelopedAndUndevelopedReservesProductionEnergy	-191000000
CY2011Q4	us-gaap	Proved Developed Reserves Boe1 ProvedDevelopedReservesBOE1	844000000
CY2012Q4	us-gaap	Proved Developed Reserves Boe1 ProvedDevelopedReservesBOE1	1047000000
CY2013Q4	us-gaap	Proved Developed Reserves Boe1 ProvedDevelopedReservesBOE1	2022000000
CY2011Q4	us-gaap	Proved Undeveloped Reserve Boe1 ProvedUndevelopedReserveBOE1	4173000000
CY2012Q4	us-gaap	Proved Undeveloped Reserve Boe1 ProvedUndevelopedReserveBOE1	3882000000
CY2013Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	224375000	shares
CY2013Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	224375000	shares
CY2012Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.10
CY2013	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	233876000	USD
CY2013	us-gaap	Interest Expense InterestExpense	136617000	USD
CY2013	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	2671573000	USD
CY2013Q4	us-gaap	Accrued Fees And Other Revenue Receivable AccruedFeesAndOtherRevenueReceivable	96825000	USD
CY2013Q4	us-gaap	Derivative Assets Current DerivativeAssetsCurrent	183000000	USD
CY2013Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	16906500	shares
CY2013Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	16791068	shares
CY2013Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	26759000	USD
CY2013Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	439575000	USD
CY2013Q4	us-gaap	Deferred Tax Liabilities Derivatives DeferredTaxLiabilitiesDerivatives	328534000	USD
CY2013Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	787346000	USD
CY2013Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	347771000	USD
CY2013Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	11000000	USD
CY2013	us-gaap	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	2000000	USD
CY2011	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	95563000	USD
CY2013Q4	us-gaap	Other Assets Current OtherAssetsCurrent	2975000	USD
CY2013Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	278580000	USD
CY2013Q4	us-gaap	Liabilities Current LiabilitiesCurrent	622229000	USD
CY2012Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.82
CY2013Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	5559656000	USD
CY2013Q4	us-gaap	Derivative Assets Noncurrent DerivativeAssetsNoncurrent	677780000	USD
CY2012Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.35
CY2012Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.25
CY2013Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	42581000	USD
CY2013Q4	arf	Other Long Term Assets Noncurrent OtherLongTermAssetsNoncurrent	720361000	USD
CY2013	arf	Derivative Instruments Gain Loss Recognized On Commodity Derivative Instrument In Income Net DerivativeInstrumentsGainLossRecognizedOnCommodityDerivativeInstrumentInIncomeNet	491689000	USD
CY2013	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	10928000	USD
CY2013	arf	Depletion Depreciation And Amortization DepletionDepreciationAndAmortization	234941000	USD
CY2013	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	425438000	USD
CY2013	us-gaap	Operating Income Loss OperatingIncomeLoss	341207000	USD
CY2013	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	162023000	USD
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	5257000	USD
CY2013	us-gaap	Net Income Loss NetIncomeLoss	-18930000	USD
CY2013	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	6574000	USD
CY2013	us-gaap	Proceeds From Issuance Of Unsecured Debt ProceedsFromIssuanceOfUnsecuredDebt	1231750000	USD
CY2013	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	71000000	USD
CY2013Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	17487000	USD
CY2012Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	174000	USD
CY2013	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-179184000	USD
CY2013	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	242000	USD
CY2011	arf	Proved Developed And Undeveloped Reserves Production Energy ProvedDevelopedAndUndevelopedReservesProductionEnergy	-89000000
CY2011	arf	Proved Developed And Undeveloped Reserves Sales Of Minerals In Place Energy ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlaceEnergy	-1000000
CY2012	arf	Proved Developed And Undeveloped Reserves Sales Of Minerals In Place Energy ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlaceEnergy	-2174000000
CY2012	arf	Proved Developed And Undeveloped Reserves Production Energy ProvedDevelopedAndUndevelopedReservesProductionEnergy	-87000000
CY2013Q4	arf	Other Long Term Liabilities Noncurrent OtherLongTermLiabilitiesNoncurrent	313693000	USD
CY2013Q4	dei	Entity Public Float EntityPublicFloat	2600000000	USD
CY2013	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	No
CY2013	dei	Entity Voluntary Filers EntityVoluntaryFilers	Yes
CY2011	arf	Proved Developed And Undeveloped Reserves Revisions Of Previous Estimates Increase Decrease Energy ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecreaseEnergy	-172000000
CY2013Q4	arf	Capitalized Costs Fresh Water Distribution Systems CapitalizedCostsFreshWaterDistributionSystems	231684000	USD
CY2012Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	2332000	USD
CY2013Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	8037000	USD
CY2013	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-42567000	USD
CY2013	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.09
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.02
CY2013	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.07
CY2013	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.09
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.02
CY2013	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.07
CY2012Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.12
CY2012Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.44
CY2012Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.32
CY2012Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.15
CY2012Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-1.70
CY2012Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.05
CY2012Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.49
CY2012Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.03
CY2012Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.10
CY2012Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.12
CY2012Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.44
CY2013	us-gaap	Share Based Compensation ShareBasedCompensation	365280000	USD
CY2013	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation And Exercise Of Stock Options AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions	323000	USD
CY2013	us-gaap	Payments To Acquire Water Systems PaymentsToAcquireWaterSystems	203790000	USD
CY2012	us-gaap	Payments To Acquire Water Systems PaymentsToAcquireWaterSystems	2801000	USD
CY2013	us-gaap	Proceeds From Issuance Initial Public Offering ProceedsFromIssuanceInitialPublicOffering	1578573000	USD
CY2011	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.04
CY2012	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.86
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.46
CY2013	us-gaap	Unrealized Gain Loss On Derivatives And Commodity Contracts UnrealizedGainLossOnDerivativesAndCommodityContracts	491689000	USD
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-1.95
CY2013	us-gaap	Repayments Of Unsecured Debt RepaymentsOfUnsecuredDebt	690000000	USD
CY2012Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.32
CY2013	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	127736000	USD
CY2013	arf	Proceeds From Settled Derivative Instruments Operating Activities ProceedsFromSettledDerivativeInstrumentsOperatingActivities	163570000	USD
CY2013	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	8506000	USD
CY2013Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	1000	USD
CY2013Q2	us-gaap	Revenues Revenues	387144000	USD
CY2013Q3	us-gaap	Revenues Revenues	384522000	USD
CY2013Q4	us-gaap	Revenues Revenues	480014000	USD
CY2013Q1	us-gaap	Operating Expenses OperatingExpenses	109923000	USD
CY2013Q2	us-gaap	Operating Expenses OperatingExpenses	138758000	USD
CY2013Q3	us-gaap	Operating Expenses OperatingExpenses	161914000	USD
CY2013Q4	us-gaap	Operating Expenses OperatingExpenses	561332000	USD
CY2013Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	-48469000	USD
CY2013Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	248386000	USD
CY2013Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	222608000	USD
CY2013Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	-81318000	USD
CY2013Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-47997000	USD
CY2013Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	131193000	USD
CY2013Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	117794000	USD
CY2012Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.15
CY2013Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-225177000	USD
CY2013Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	3100000	USD
CY2013Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	2157000	USD
CY2013Q1	us-gaap	Net Income Loss NetIncomeLoss	-47997000	USD
CY2013Q2	us-gaap	Net Income Loss NetIncomeLoss	131193000	USD
CY2013Q3	us-gaap	Net Income Loss NetIncomeLoss	120894000	USD
CY2013Q4	us-gaap	Net Income Loss NetIncomeLoss	-223020000	USD
CY2013	us-gaap	Payments To Acquire Oil And Gas Equipment PaymentsToAcquireOilAndGasEquipment	389453000	USD
CY2012	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	20210000	USD
CY2011	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	11915000	USD
CY2013	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	50481000	USD
CY2013	arf	Maximum Effect Of Dilutive Securities Stock Options And Restrictive Stock Units MaximumEffectOfDilutiveSecuritiesStockOptionsAndRestrictiveStockUnits	0.01
CY2013	arf	Adjustments To Additional Paid In Capital Contribution Sharebased Compensation Of Affiliate AdjustmentsToAdditionalPaidInCapitalContributionSharebasedCompensationOfAffiliate	364957000	USD
CY2011	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.50
CY2012	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.09
CY2012Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-1.70
CY2011	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.04
CY2012	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.86
CY2011	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.46
CY2012	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-1.95
CY2013	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="font-size:10.0pt;font-family:Times New Roman;"> <p style="FONT-FAMILY: times;"><font size="2"><b><i>(r)   Reclassifications</i></b></font></p> <p style="FONT-FAMILY: times;"><font size="2">        Certain reclassifications have been made to prior periods' financial information related to water distribution assets to conform to the 2013 presentation.</font></p> </div>
CY2011	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.50
CY2012	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.09
CY2012Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.05
CY2012Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.35
CY2012Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.25
CY2012Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.82
CY2012Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.49
CY2012Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.03
CY2013Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.18
CY2013Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.50
CY2013Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.45
CY2013Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.86
CY2013Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.01
CY2013Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.01
CY2013Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.18
CY2013Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
CY2013Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.46
CY2013Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.85
CY2013Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.18
CY2013Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.50
CY2013Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.45
CY2013Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.86
CY2013Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.01
CY2013Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.01
CY2013Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.18
CY2013Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.50
CY2013Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2013Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.85
CY2013	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	121000000	USD
CY2011	arf	Derivative Instruments Gain Loss Recognized On Interest Rate Derivative Instrument In Income Net DerivativeInstrumentsGainLossRecognizedOnInterestRateDerivativeInstrumentInIncomeNet	-94000	USD

Files In Submission

Name	View Source	Status
0001047469-14-001424-index-headers.html	Edgar Link	pending
0001047469-14-001424-index.html	Edgar Link	pending
0001047469-14-001424.txt	Edgar Link	pending
0001047469-14-001424-xbrl.zip	Edgar Link	pending
a2218464z10-k.htm	Edgar Link	pending
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arf-20131231.xml	Edgar Link	completed
arf-20131231.xsd	Edgar Link	pending
arf-20131231_cal.xml	Edgar Link	unprocessable
arf-20131231_def.xml	Edgar Link	unprocessable
arf-20131231_lab.xml	Edgar Link	unprocessable
arf-20131231_pre.xml	Edgar Link	unprocessable
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xls	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
g604693.jpg	Edgar Link	pending
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report.css	Edgar Link	pending
Show.js	Edgar Link	pending

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2014 Q1 Form 10-K Financial Statement

#000104746914001424 Filed on February 27, 2014

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

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$AR ANTERO RESOURCES Corp Stock $ar

2014 Q1 Form 10-K Financial Statement

#000104746914001424 Filed on February 27, 2014

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AR
ANTERO RESOURCES Corp Stock $ar