Name:	ar_GainLossOnExchangeOfAcreageAndOwnershipInterest
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The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties relating to leases as the estimate of future successful production from these properties is reduced.

No definition available.

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Represents the expense recorded to reduce the value of oil and gas assets consisting of proved properties as the estimate of future successful production from these properties is reduced.

No definition available.

Name:	ar_ImpairmentOfOilAndGasPropertiesProved
Namespace Prefix:	ar_
Data Type:	xbrli:monetaryItemType
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The acres of land delivered on non-cash exchange of acreage and ownership interest related to proved properties

No definition available.

Name:	ar_LandDeliveredInExchange
Namespace Prefix:	ar_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

The acres of land received on non-cash exchange of acreage and ownership interest related to proved properties

No definition available.

Name:	ar_LandReceivedInExchange
Namespace Prefix:	ar_
Data Type:	num:areaItemType
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Exploration expenses (including prospecting) related to oil and gas producing entities and would be included in operating expenses of that entity. Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are: (i) Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those studies. Collectively, these are sometimes referred to as geological and geophysical or "G&G" costs. (ii) Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records. (iii) Dry hole contributions and bottom hole contributions. (iv) Costs of drilling and equipping exploratory wells. (v) Costs of drilling exploratory-type stratigraphic test wells.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 23
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62136-109447

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The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 35
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66906256&loc=d3e66150-109466

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- References

No definition available.