| **Business Segments (Details) (USD $)In Thousands, unless otherwise specified** | 3 Months Ended                                                                                                                                                                                | 6 Months Ended |
|---------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
||
| **Segment Reporting Information [Line Items]**                                  |                                                                                                                                                                                          |                |   |  |   |   |
| Number of reportable segments                                                   |                                                                                                                                                                                          |                |   |  | 3us-gaap_NumberOfReportableSegments |   |
| **Segment Reporting Information [Abstract]**                                    |                                                                                                                                                                                          |                |   |  |   |   |
| Revenues from external customers                                                | $ 424,924us-gaap_RegulatedAndUnregulatedOperatingRevenue                                                                                                                                      | [1]            | $ 462,247us-gaap_RegulatedAndUnregulatedOperatingRevenue | [1] | $ 1,032,196us-gaap_RegulatedAndUnregulatedOperatingRevenue | $ 1,119,980us-gaap_RegulatedAndUnregulatedOperatingRevenue |
| Margin                                                                          | 225,621us-gaap_GrossProfit                                                                                                                                                                    |                | 211,523us-gaap_GrossProfit |  | 495,691us-gaap_GrossProfit | 473,035us-gaap_GrossProfit |
| Operations and maintenance expenses                                             | 71,453pny_SegmentReportingInformationOperationsAndMaintenanceExpenses                                                                                                                         |                | 70,214pny_SegmentReportingInformationOperationsAndMaintenanceExpenses |  | 137,672pny_SegmentReportingInformationOperationsAndMaintenanceExpenses | 130,878pny_SegmentReportingInformationOperationsAndMaintenanceExpenses |
| Income from equity method investments                                           | 15,842us-gaap_IncomeLossFromEquityMethodInvestments                                                                                                                                           |                | 14,360us-gaap_IncomeLossFromEquityMethodInvestments |  | 24,107us-gaap_IncomeLossFromEquityMethodInvestments | 24,302us-gaap_IncomeLossFromEquityMethodInvestments |
| Operating income (loss) before income taxes                                     | 111,498pny_SegmentOperatingIncomeLossBeforeIncomeTaxes                                                                                                                                        |                | 103,464pny_SegmentOperatingIncomeLossBeforeIncomeTaxes |  | 273,376pny_SegmentOperatingIncomeLossBeforeIncomeTaxes | 265,477pny_SegmentOperatingIncomeLossBeforeIncomeTaxes |
| Income before income taxes for reportable segments                              | 108,727us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest                                                                                    |                | 103,334us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest |  | 261,240us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | 264,436us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest |
| **Segment Reporting Information, Operating Income (Loss) [Abstract]**           |                                                                                                                                                                                          |                |   |  |   |   |
| Utility income taxes                                                            | (36,409)pny_OperatingIncomeTaxExpenseBenefit                                                                                                                                                  |                | (36,190)pny_OperatingIncomeTaxExpenseBenefit |  | (92,680)pny_OperatingIncomeTaxExpenseBenefit | (95,992)pny_OperatingIncomeTaxExpenseBenefit |
| Operating income                                                                | 75,123us-gaap_OperatingIncomeLoss                                                                                                                                                             |                | 67,299us-gaap_OperatingIncomeLoss |  | 180,882us-gaap_OperatingIncomeLoss | 169,618us-gaap_OperatingIncomeLoss |
| **Segment Reporting Information, Profit (Loss) [Abstract]**                     |                                                                                                                                                                                          |                |   |  |   |   |
| Income before income taxes for reportable segments                              | 108,727us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest                                                                                    |                | 103,334us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest |  | 261,240us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest | 264,436us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest |
| Income taxes                                                                    | (42,325)us-gaap_IncomeTaxExpenseBenefit                                                                                                                                                       |                | (40,794)us-gaap_IncomeTaxExpenseBenefit |  | (101,860)us-gaap_IncomeTaxExpenseBenefit | (104,324)us-gaap_IncomeTaxExpenseBenefit |
| Net Income                                                                      | 66,402us-gaap_NetIncomeLoss                                                                                                                                                                   |                | 62,540us-gaap_NetIncomeLoss |  | 159,380us-gaap_NetIncomeLoss | 160,112us-gaap_NetIncomeLoss |
| Regulated Operation                                                             |                                                                                                                                                                                          |                |   |  |   |   |
| **Segment Reporting Information [Abstract]**                                    |                                                                                                                                                                                          |                |   |  |   |   |
| Revenues from external customers                                                | 424,924us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember                                                               |                | 462,247us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 1,032,196us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 1,119,980us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Margin                                                                          | 225,621us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember                                                                                           |                | 211,523us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 495,691us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 473,035us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Operations and maintenance expenses                                             | 71,424pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember                                                |                | 70,193pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 137,574pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 130,832pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Income from equity method investments                                           | 0us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember                                                                       |                | 0us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 0us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 0us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Operating income (loss) before income taxes                                     | 111,532pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember                                                               |                | 103,489pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 273,562pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 265,610pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Income before income taxes for reportable segments                              | 92,918us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember            |                | 88,999us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 237,318us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 240,268us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| **Segment Reporting Information, Profit (Loss) [Abstract]**                     |                                                                                                                                                                                          |                |   |  |   |   |
| Income before income taxes for reportable segments                              | 92,918us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember            |                | 88,999us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |  | 237,318us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember | 240,268us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= us-gaap_RegulatedOperationMember |
| Non Utility Regulated Activities                                                |                                                                                                                                                                                          |                |   |  |   |   |
| **Segment Reporting Information [Abstract]**                                    |                                                                                                                                                                                          |                |   |  |   |   |
| Revenues from external customers                                                | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                                              |                | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Margin                                                                          | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                                                                          |                | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Operations and maintenance expenses                                             | 20pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                             |                | 8pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 51pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 14pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Income from equity method investments                                           | 3,577us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                                            |                | 2,467us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 7,348us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 5,574us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Operating income (loss) before income taxes                                     | (20)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                                           |                | (8)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | (51)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | (14)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Income before income taxes for reportable segments                              | 3,557us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember      |                | 2,459us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 7,297us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 5,560us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| **Segment Reporting Information, Operating Income (Loss) [Abstract]**           |                                                                                                                                                                                          |                |   |  |   |   |
| Segment Operating Income Before Income Taxes                                    | 20pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember                                                                 |                | 8pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 51pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 14pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| **Segment Reporting Information, Profit (Loss) [Abstract]**                     |                                                                                                                                                                                          |                |   |  |   |   |
| Income before income taxes for reportable segments                              | 3,557us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember      |                | 2,459us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |  | 7,297us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember | 5,560us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityRegulatedActivitiesMember |
| Non Utility Unregulated Activities                                              |                                                                                                                                                                                          |                |   |  |   |   |
| **Segment Reporting Information [Abstract]**                                    |                                                                                                                                                                                          |                |   |  |   |   |
| Revenues from external customers                                                | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                                            |                | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 0us-gaap_RegulatedAndUnregulatedOperatingRevenue/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| Margin                                                                          | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                                                                        |                | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 0us-gaap_GrossProfit/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| Operations and maintenance expenses                                             | 9pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                            |                | 13pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 47pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 32pny_SegmentReportingInformationOperationsAndMaintenanceExpenses/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| Income from equity method investments                                           | 12,265us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                                         |                | 11,893us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 16,759us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 18,728us-gaap_IncomeLossFromEquityMethodInvestments/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| Operating income (loss) before income taxes                                     | (14)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                                         |                | (17)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | (135)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | (119)pny_SegmentOperatingIncomeLossBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| Income before income taxes for reportable segments                              | 12,252us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember   |                | 11,876us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 16,625us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 18,608us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| **Segment Reporting Information, Operating Income (Loss) [Abstract]**           |                                                                                                                                                                                          |                |   |  |   |   |
| Segment Operating Income Before Income Taxes                                    | 14pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember                                                               |                | 17pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | 135pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | 119pny_SegmentOperatingIncomeBeforeIncomeTaxes/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
| **Segment Reporting Information, Profit (Loss) [Abstract]**                     |                                                                                                                                                                                          |                |   |  |   |   |
| Income before income taxes for reportable segments                              | $ 12,252us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |                | $ 11,876us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |  | $ 16,625us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember | $ 18,608us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest/ us-gaap_StatementBusinessSegmentsAxis= pny_NonUtilityUnregulatedActivitiesMember |
|                                                                                 |
| [1]See Note 12 for amounts attributable to affiliates.                          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The component of income tax expense for the period representing amounts of income taxes paid or payable as determined by applying the provisions for relevant enacted tax laws to relevant amounts of utility taxable income (loss).
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of operating income or loss for the reportable segment before income taxes and extraordinary items
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of operating income or loss for the reportable segment before income taxes and extraordinary items
+ References
No definition available.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of operations and maintenance expenses included in measure of segment profit or loss
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1,2) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.
+ References
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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.
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The net result for the period of deducting operating expenses from operating revenues.
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The total amount of operating revenues recognized during the period.
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