Contingencies (Details) - Pending Litigation $ in Millions	Mar. 31, 2017 USD ($) contract lawsuit
SJGC
Contingencies
Number of lawsuits \| lawsuit	2
Number of long term gas contracts \| contract	2
WGL
Contingencies
Number of long term gas contracts \| contract	2
WGL \| Minimum
Contingencies
Damages sought \| $	$ 30.0
Potential Positive Outcome of Litigation \| SJGC
Contingencies
Additional accounts receivable \| $	$ 56.0

Amount the entity estimates it is due from a customer in excess of the amount paid by the customer.

No definition available.

Name:	ar_AdditionalAccountsReceivable
Namespace Prefix:	ar_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the number of lawsuits to which the entity is subject related to a sales contract.

+ References

No definition available.

+ Details

Name:	ar_NumberOfLawsuits
Namespace Prefix:	ar_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of long term gas contracts.

+ References

No definition available.

+ Details

Name:	ar_NumberOfLongTermGasContracts
Namespace Prefix:	ar_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LitigationCaseAxis=ar_SouthJerseyGasCompanyAndSouthJerseyResourcesGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationCaseAxis=ar_WashingtonGasLightCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GainContingenciesByNatureAxis=us-gaap_PositiveOutcomeOfLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: