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

Computation of oil, natural gas and NGL reserves.

+ References

No definition available.

+ Details

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

- Definition

Mineral acreage acquired.

+ References

No definition available.

+ Details

Name:	phx_MineralAcreageAcquired
Namespace Prefix:	phx_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ 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=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228

+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

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

- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ 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=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
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=stpr_NM
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_TX
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_BlaineAndCaddoCountiesOklahomaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Properties And Equipment (Details)	3 Months Ended				9 Months Ended
Properties And Equipment (Details)	Jun. 30, 2019 USD ($) a	Mar. 31, 2019 USD ($) a	Dec. 31, 2018 USD ($) a	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) a	Jun. 30, 2018 USD ($)
Property Plant And Equipment [Line Items]
Gain on sale of oil and gas properties	$ 4,017,787				$ 13,114,725
Computation of Oil, Natural Gas and NGL Reserves					12 months
Impairment	$ 0			$ 0	$ 0	$ 0
Lea and Eddy Counties, New Mexico [Member]
Property Plant And Equipment [Line Items]
Mineral acreage sold \| a			206
Proceeds from sales of assets			$ 9,096,938
Gain on sale of oil and gas properties			$ 9,096,938
Martin County, Texas [Member]
Property Plant And Equipment [Line Items]
Mineral acreage sold \| a	166				166
Proceeds from sales of assets	$ 4,018,031
Gain on sale of oil and gas properties	$ 4,017,787
Blaine County, Oklahoma [Member]
Property Plant And Equipment [Line Items]
Mineral acreage acquired \| a			45
Purchase price of mineral acreage acquired			$ 423,000
Blaine and Caddo Counties, Oklahoma [Member]
Property Plant And Equipment [Line Items]
Mineral acreage acquired \| a		329
Purchase price of mineral acreage acquired		$ 1,386,775
Bakken/Three Forks, Dakota and STACK Blaine County, Oklahoma [Member]
Property Plant And Equipment [Line Items]
Mineral acreage acquired \| a	313
Purchase price of mineral acreage acquired	$ 3,310,691