Consolidated cash balance in anti-cash hoarding provision.

No definition available.

Name:	phx_ConsolidatedCashBalanceInAntiCashHoardingProvision
Namespace Prefix:	phx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt Instrument Covenant Compliance, Current Ratio

+ References

No definition available.

+ Details

Name:	phx_DebtInstrumentCovenantComplianceCurrentRatio
Namespace Prefix:	phx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument Covenant Compliance, Funded Debt To Earnings Before Interest, Taxes, Depreciation, And Amortization Ratio

+ References

No definition available.

+ Details

Name:	phx_DebtInstrumentCovenantComplianceFundedDebtToEarningsBeforeInterestTaxesDepreciationAndAmortizationRatio
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

Secured borrowing base credit facility, quarterly reduction amount.

+ References

No definition available.

+ Details

Name:	phx_SecuredBorrowingBaseCreditFacilityQuarterlyReductionAmount
Namespace Prefix:	phx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Secured borrowing base credit facility quarterly reduction term description.

+ References

No definition available.

+ Details

Name:	phx_SecuredBorrowingBaseCreditFacilityQuarterlyReductionTermDescription
Namespace Prefix:	phx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Swap agreement period.

+ References

No definition available.

+ Details

Name:	phx_SwapAgreementPeriod
Namespace Prefix:	phx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Definition

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

+ References

+ 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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_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:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt (Details) - Revolving Credit Facility [Member] - USD ($)			6 Months Ended
	Dec. 04, 2020	Jun. 24, 2020	Mar. 31, 2021
Line Of Credit Facility [Line Items]
Revolving loan credit facility			$ 200,000,000
Borrowing base of credit facility	$ 30,000,000		$ 29,400,000
Credit facility maturity			Nov. 30, 2022
Effective Interest rate			4.00%
Debt issuance cost net of amortization			$ 195,073
Borrowing base of credit facility, quarterly reduction amount	$ 600,000	$ 1,000,000
Borrowing base of credit facility, quarterly reduction term description	The amendment reduced the Quarterly Commitment Reductions from $1,000,000 to $600,000
Consolidated cash balance in anti-cash hoarding provision	$ 1,000,000	$ 2,000,000
Funded debt to EBITDA ratio	350.00%	400.00%	350.00%
Swap agreement period			18 months
Credit facility outstanding amount			$ 23,500,000
Availability under outstanding credit facility			$ 5,900,000
Minimum [Member]
Line Of Credit Facility [Line Items]
Current ratio			100.00%
Minimum [Member] \| Prime Rate [Member]
Line Of Credit Facility [Line Items]
Interest rate basis			1.00%
Minimum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line Of Credit Facility [Line Items]
Interest rate basis			2.50%
Maximum [Member] \| Prime Rate [Member]
Line Of Credit Facility [Line Items]
Interest rate basis			1.75%
Maximum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line Of Credit Facility [Line Items]
Interest rate basis			3.25%