Area of mineral acreage sold.

No definition available.

Name:	phx_AreaOfMineralAcreageSold
Namespace Prefix:	phx_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of gain (loss) on sale or disposal of oil and gas property or timber property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_StatementGeographicalAxis=phx_CentralBasinPlatformMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_OK
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=phx_EddyCountryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Properties And Equipment - Summary of Divestitures (Details)	3 Months Ended				9 Months Ended
	Jun. 30, 2021 USD ($) a	Sep. 30, 2020 USD ($) a	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($) a	Jun. 30, 2021 USD ($) a	Jun. 30, 2020 USD ($)
Property Plant And Equipment [Line Items]
Sale Price					$ 533,371	$ 3,457,500
Gain/(Loss)	$ 270,070		$ 3,108		$ 313,595	$ 3,275,996
Central Basin Platform, TX [Member]
Property Plant And Equipment [Line Items]
Net mineral acres \| a	2,857				2,857
Sale Price	$ 300,000
Gain/(Loss)	$ 200,000
Northwest OK [Member]
Property Plant And Equipment [Line Items]
Net mineral acres \| a		5,925
Sale Price		$ 800,000
Gain/(Loss)		$ 700,000
Eddy Country, NM [Member]
Property Plant And Equipment [Line Items]
Net mineral acres \| a				530
Sale Price				$ 3,400,000
Gain/(Loss)				$ 3,300,000