Allocated share based compensation expense (benefit).

No definition available.

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Namespace Prefix:	arex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Payments to vested awards.

+ References

No definition available.

+ Details

Name:	arex_PaymentsToVestedAwards
Namespace Prefix:	arex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate fair market value of the shares subject to performance conditions.

+ References

No definition available.

+ Details

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Namespace Prefix:	arex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements payable within one year (or the normal operating cycle, if longer). Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20028-108363

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 25
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=75028277&loc=d3e19793-108362

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements payable after one year (or the normal operating cycle, if longer). Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Number of non-vested options outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_ExecutiveOfficerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=arex_CashSettledPerformanceAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=arex_RestrictedSharesCumulativeShareholderReturnPerformanceStockAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=arex_CashSettledPerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix:
Data Type:	na
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Period Type:

Share-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017
Executive Officers [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Service period	3 years
Cash Settled Performance Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of unvested share awards outstanding	1,508,286	1,508,286
Payments to vested awards		$ 1.0
Cash Settled Performance Awards [Member] \| Executive Officers [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share awards	774,590
Fair market value of shares	$ 2.4
Restricted Shares Total Shareholder Return Performance Stock Awards [Member] \| Executive Officers [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share awards	387,295
Fair market value of shares	$ 0.8
Cash Settled Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, current liability	0.8	0.8
Share-based compensation, non-current liability	$ 0.6	0.6
Cash Settled Performance Shares [Member] \| General and Administrative Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation (benefit) expense		$ 0.3	$ (0.1)