Area held per tract.

No definition available.

Name:	phx_AreaHeldPerTract
Namespace Prefix:	phx_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Area of non producing minerals.

+ References

No definition available.

+ Details

Name:	phx_AreaOfNonProducingMinerals
Namespace Prefix:	phx_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Cliff vesting term of restricted stock units period.

+ References

No definition available.

+ Details

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

- Definition

Insignificant fields straight-line amortization period.

+ References

No definition available.

+ Details

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

- Definition

Mineral rights accumulated period.

+ References

No definition available.

+ Details

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

- Definition

Non producing minerals amortization period.

+ References

No definition available.

+ Details

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

- Definition

Non producing minerals book value net.

+ References

No definition available.

+ Details

Name:	phx_NonProducingMineralsBookValueNet
Namespace Prefix:	phx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of tracts owned.

+ References

No definition available.

+ Details

Name:	phx_NumberOfTractsOwned
Namespace Prefix:	phx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage holding of mineral interest.

+ References

No definition available.

+ Details

Name:	phx_PercentageHoldingOfMineralInterest
Namespace Prefix:	phx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage Of Oil, Natural Gas Liquids, And Natural Gas Sales Were Derived From Sale Of Natural Gas

+ References

No definition available.

+ Details

Name:	phx_PercentageOfOilNaturalGasLiquidsAndNaturalGasSalesWereDerivedFromSaleOfNaturalGas
Namespace Prefix:	phx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of oil, natural gas liquids and natural gas sales were derived from sale of natural gas liquids.

+ References

No definition available.

+ Details

Name:	phx_PercentageOfOilNaturalGasLiquidsAndNaturalGasSalesWereDerivedFromSaleOfNaturalGasLiquids
Namespace Prefix:	phx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of oil, natural gas liquids and natural gas sales were derived from sale of oil.

+ References

No definition available.

+ Details

Name:	phx_PercentageOfOilNaturalGasLiquidsAndNaturalGasSalesWereDerivedFromSaleOfOil
Namespace Prefix:	phx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Producing minerals straight-line amortization period.

+ References

No definition available.

+ Details

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

- Definition

Summary Of Significant Accounting Policies [Line Items]

+ References

No definition available.

+ Details

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

- Definition

Number of producing oil wells and oil wells capable of production with working interest ownership.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1208
-Paragraph (a)

+ Details

Name:	srt_ProductiveOilWellsNumberOfWellsGross
Namespace Prefix:	srt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest capitalized during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

Name:	us-gaap_InterestCostsCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Total interest costs incurred during the period and either capitalized or charged against earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

Name:	us-gaap_InterestCostsIncurred
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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

- Definition

Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(5))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

+ Details

Name:	us-gaap_ProvisionForDoubtfulAccounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_ProductConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=phx_OilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=srt_NaturalGasLiquidsReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=phx_NaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Sep. 30, 2021 USD ($) a Item	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of Oil, NGL and Natural Gas Production Units \| Item	6,457
Oil, NGL and natural gas revenues were derived from the sale of natural gas	56.00%
Oil, NGL and natural gas revenues were derived from the sale of oil	34.00%
Oil, NGL and natural gas revenues were derived from the sale of NGL	10.00%
Bad debt expense	$ 0	$ 0	$ 0
Book value of Non-producing oil and natural gas	$ 32,542,709	13,556,020
Percentage of perpetual ownership of mineral interests in Oklahoma, North Dakota, Texas, Arkansas and New Mexico	61.00%
Accumulated period perpetual rights	95 years
Non Producing Minerals Area \| a	187,386
Number of tracts owned \| Item	6,309
Amount of acres average tract contains \| a	30
Amortized Period of Non-producing Minerals	33 years
Straight-line amortized period of Producing Minerals	20 years
Straight-line amortized period of insignificant fields	10 years
Amount of Capitalized Interest Included in the Company's Capital Expenditures	$ 0	0	38,606
Interest Expense	$ 995,127	$ 1,286,788	$ 1,995,789
Effective tax rate	(9.00%)	(26.00%)
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of furniture and fixtures	5 years
Restricted Stock Awards, vesting period	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of furniture and fixtures	8 years
Sales Revenue, Net [Member] \| Product Concentration Risk [Member] \| Oil [Member]
Summary Of Significant Accounting Policies [Line Items]
Total sale volume from sale of Oil, NGL and Natural gas	15.00%
Sales Revenue, Net [Member] \| Product Concentration Risk [Member] \| NGL [Member]
Summary Of Significant Accounting Policies [Line Items]
Total sale volume from sale of Oil, NGL and Natural gas	11.00%
Sales Revenue, Net [Member] \| Product Concentration Risk [Member] \| Natural Gas [Member]
Summary Of Significant Accounting Policies [Line Items]
Total sale volume from sale of Oil, NGL and Natural gas	74.00%