Discounting rate of company reserves.

No definition available.

Name:	phx_DiscountingRateOfCompanyReserves
Namespace Prefix:	phx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Secured borrowing base credit facility.

+ References

No definition available.

+ Details

Name:	phx_SecuredBorrowingBaseCreditFacility
Namespace Prefix:	phx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of securities received as collateral from a counterparty that were re-pledged, sold, delivered or otherwise reused by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=55761124&loc=SL6224234-111729

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Long-Term Debt (Details) - USD ($)	12 Months Ended
Long-Term Debt (Details) - USD ($)	Sep. 30, 2015	Dec. 10, 2015	Dec. 09, 2015	Jun. 17, 2014
Line Of Credit Facility [Line Items]
Revolving loan credit facility				$ 200,000,000
Discount rate	8.00%
Borrowing base of credit facility		$ 100,000,000	$ 120,000,000
Secured by carrying value	$ 166,401,695
Credit facility maturity	Nov. 30, 2018
Effective Interest rate	2.37%
Minimum [Member] \| Prime Rate [Member]
Line Of Credit Facility [Line Items]
Interest rate basis	0.375%
Minimum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line Of Credit Facility [Line Items]
Interest rate basis	1.875%
Maximum [Member] \| Prime Rate [Member]
Line Of Credit Facility [Line Items]
Interest rate basis	1.125%
Maximum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line Of Credit Facility [Line Items]
Interest rate basis	2.625%