| **Equity Method Investments (Details) (USD $)**             | 3 Months Ended                                                                                                                                                                                                          | 6 Months Ended                                                                                                                                                                            |                                                                                                                                                                                                                         |
|-------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Related party costs                                         | $ 7,297,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty                                                                                                                                      | $ 7,257,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty                                                                                                        | $ 14,770,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty                                                                                                                                     | $ 14,715,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty |   |
| Trade accounts payable                                      | 2,451,000us-gaap_DueToRelatedPartiesCurrent                                                                                                                                                                             |                                                                                                                                                                                      | 2,451,000us-gaap_DueToRelatedPartiesCurrent                                                                                                                                                                             |   | 2,510,000us-gaap_DueToRelatedPartiesCurrent |
| Contributions to equity method investments                  |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 15,495,000us-gaap_PaymentsToAcquireEquityMethodInvestments                                                                                                                                                              | 18,600,000us-gaap_PaymentsToAcquireEquityMethodInvestments |   |
| Atlantic Coast Pipeline                                     |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 10.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                          |                                                                                                                                                                                      | 10.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                          |   |   |
| Contributions to equity method investments                  | 700,000us-gaap_PaymentsToAcquireEquityMethodInvestments/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                          |                                                                                                                                                                                      | 5,800,000us-gaap_PaymentsToAcquireEquityMethodInvestments/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                        |   |   |
| Target Pipeline In Service Date                             |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 2018                                                                                                                                                                                                                    |   |   |
| Long term purchase commitment time period                   |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 20 years                                                                                                                                                                                                                |   |   |
| Estimated Percentage Project Financing                      |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 70.00%pny_EstimatedPercentageProjectFinancing/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                                    |   |   |
| Estimated Percentage Debt Financing                         |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 50.00%pny_EstimatedPercentageDebtFinancing/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                                       |   |   |
| Estimated Percentage Equity Financing                       |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 50.00%pny_EstimatedPercentageEquityFinancing/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                                                     |   |   |
| Funding Obligation Under Equity Contribution Agreements     |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 15,200,000pny_MaximumFundingObligationUnderEquityContributionAgreements/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember                                          |   |   |
| Cardinal Pipeline Company                                   |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 21.49%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                                                        |                                                                                                                                                                                      | 21.49%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                                                        |   |   |
| Related party costs                                         | 2,135,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                               | 2,164,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember | 4,349,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                               | 4,404,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember |   |
| Trade accounts payable                                      | 720,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                                                                      |                                                                                                                                                                                      | 720,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember                                                                      |   | 747,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_CardinalPipelineCompanyMember |
| Constitution Pipeline Company                               |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 24.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                                    |                                                                                                                                                                                      | 24.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                                    |   |   |
| Estimated Pipeline Costs Including AFUDC                    | 875,000,000pny_EstimatedPipelineDevelopmentAndConstructionCostsIncludingAFUDC/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                              |                                                                                                                                                                                      | 875,000,000pny_EstimatedPipelineDevelopmentAndConstructionCostsIncludingAFUDC/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                              |   |   |
| Estimated Pipeline Costs Excluding AFUDC                    | 785,000,000pny_EstimatedPipelineDevelopmentAndConstructionCostsExcludingAFUDC/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                              |                                                                                                                                                                                      | 785,000,000pny_EstimatedPipelineDevelopmentAndConstructionCostsExcludingAFUDC/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                              |   |   |
| Contributions to equity method investments                  | 4,800,000us-gaap_PaymentsToAcquireEquityMethodInvestments/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                                  |                                                                                                                                                                                      | 9,700,000us-gaap_PaymentsToAcquireEquityMethodInvestments/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                                  |   |   |
| Total equity contribution for the project                   | 63,300,000pny_TotalContributionsToEquityMethodInvestmentsForProject/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                        |                                                                                                                                                                                      | 63,300,000pny_TotalContributionsToEquityMethodInvestmentsForProject/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_ConstitutionPipelineCompanyMember                                        |   |   |
| Target Pipeline In Service Date                             |                                                                                                                                                                                                                    |                                                                                                                                                                                      | 2016                                                                                                                                                                                                                    |   |   |
| Hardy Storage                                               |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                                                   |                                                                                                                                                                                      | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                                                   |   |   |
| Related party costs                                         | 2,322,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                          | 2,392,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember            | 4,645,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                          | 4,817,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember |   |
| Trade accounts payable                                      | 774,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                                                                 |                                                                                                                                                                                      | 774,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember                                                                                 |   | 774,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_HardyStorageMember |
| Pine Needle Company                                         |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 45.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                                              |                                                                                                                                                                                      | 45.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                                              |   |   |
| Related party costs                                         | 2,840,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                     | 2,701,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember       | 5,776,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                     | 5,494,000us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember |   |
| Trade accounts payable                                      | 957,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                                                            |                                                                                                                                                                                      | 957,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember                                                                            |   | 989,000us-gaap_DueToRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_PineNeedleCompanyMember |
| South Star Energy Services                                  |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Membership interest percentage                              | 15.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                        |                                                                                                                                                                                      | 15.00%us-gaap_EquityMethodInvestmentOwnershipPercentage/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                        |   |   |
| Operating revenues                                          | 187,000us-gaap_RevenueFromRelatedParties/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                                       | 475,000us-gaap_RevenueFromRelatedParties/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                         | 583,000us-gaap_RevenueFromRelatedParties/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                                       | 907,000us-gaap_RevenueFromRelatedParties/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember |   |
| Trade accounts receivable                                   | 177,000us-gaap_DueFromRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                                    |                                                                                                                                                                                      | 177,000us-gaap_DueFromRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember                                                                    |   | 460,000us-gaap_DueFromRelatedPartiesCurrent/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_SouthStarEnergyServicesMember |
| Minimum | Atlantic Coast Pipeline                           |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Estimated Pipeline Development And Construction Costs       | 4,500,000,000pny_EstimatedPipelineDevelopmentAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember      |                                                                                                                                                                                      | 4,500,000,000pny_EstimatedPipelineDevelopmentAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember      |   |   |
| Estimated Contributions For Pipeline And Construction Costs | 225,000,000pny_EstimatedContributionsForPipelineAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember   |                                                                                                                                                                                      | 225,000,000pny_EstimatedContributionsForPipelineAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember   |   |   |
| Maximum | Atlantic Coast Pipeline                           |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| **Schedule of Equity Method Investments [Line Items]**      |                                                                                                                                                                                                                    |                                                                                                                                                                                      |                                                                                                                                                                                                                    |   |   |
| Estimated Pipeline Development And Construction Costs       | 5,000,000,000pny_EstimatedPipelineDevelopmentAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember      |                                                                                                                                                                                      | 5,000,000,000pny_EstimatedPipelineDevelopmentAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember      |   |   |
| Estimated Contributions For Pipeline And Construction Costs | $ 250,000,000pny_EstimatedContributionsForPipelineAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember |                                                                                                                                                                                      | $ 250,000,000pny_EstimatedContributionsForPipelineAndConstructionCosts/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis= pny_AtlanticCoastPipelineMember |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The estimated cash outflow associated with contributions to an equity method investment (EMI) to fund the EMI's development and construction of a new natural gas pipeline.
+ References
No definition available.
+ Details**Name:**pny_EstimatedContributionsForPipelineAndConstructionCosts**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The estimated percentage of debt financing the joint members expect to obtain for equity method investment (EMI) when EMI is operational.
+ References
No definition available.
+ Details**Name:**pny_EstimatedPercentageDebtFinancing**Namespace Prefix:**pny_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The estimated percentage of equity financing the joint members expect to obtain for equity method investment (EMI) when EMI is operational.
+ References
No definition available.
+ Details**Name:**pny_EstimatedPercentageEquityFinancing**Namespace Prefix:**pny_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The estimated percentage of financing the joint venture members expect to obtain to finance the project.
+ References
No definition available.
+ Details**Name:**pny_EstimatedPercentageProjectFinancing**Namespace Prefix:**pny_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total estimated cost pertaining to the development and construction of new pipeline.
+ References
No definition available.
+ Details**Name:**pny_EstimatedPipelineDevelopmentAndConstructionCosts**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total estimated cost pertaining to the development and construction of the new pipeline, excluding an allowance for funds used during construction (AFUDC).
+ References
No definition available.
+ Details**Name:**pny_EstimatedPipelineDevelopmentAndConstructionCostsExcludingAFUDC**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total estimated cost pertaining to the development and construction of the new pipeline, including an allowance for funds used during construction (AFUDC).
+ References
No definition available.
+ Details**Name:**pny_EstimatedPipelineDevelopmentAndConstructionCostsIncludingAFUDC**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum funding obligation, per Equity Contribution Agreement, that Company has committed to make funds available to Company's subsidiary for it to pay and perform its obligations under an Limited Liability Company Agreement.
+ References
No definition available.
+ Details**Name:**pny_MaximumFundingObligationUnderEquityContributionAgreements**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The target date for the pipeline to be placed into service.
+ References
No definition available.
+ Details**Name:**pny_TargetPipelineInServiceDate**Namespace Prefix:**pny_**Data Type:**xbrli:gYearItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The total cash outflow associated with advances to an equity method investments, which are investments in joint ventures.
+ References
No definition available.
+ Details**Name:**pny_TotalContributionsToEquityMethodInvestmentsForProject**Namespace Prefix:**pny_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle).
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 2 -Article 4
+ Details**Name:**us-gaap_DueFromRelatedPartiesCurrent**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).
+ 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(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571
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| X                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
+ Details**Name:**us-gaap_LongtermPurchaseCommitmentPeriod**Namespace Prefix:**us-gaap_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3213-108585
+ Details**Name:**us-gaap_PaymentsToAcquireEquityMethodInvestments**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.
+ References
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| - Definition
Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.
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