1.0.0.3 false CONSOLIDATED STATEMENTS of CASH FLOWS (USD $) In Millions false 1 $ false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 2 $ false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 3 $ false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 5 Operating activities 3 us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 6 Net income 4 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 761000000 761 false false 2 true true 836000000 836 false false 3 true true 496000000 496 false false No definition available. No authoritative reference available. false 7 Adjustments to reconcile net income to net cash provided by operating activities 4 us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 8 Depreciation, amortization and accretion 5 us-gaap_DepreciationAmortizationAndAccretionNet us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 1135000000 1135 false false 2 false true 957000000 957 false false 3 false true 1026000000 1026 false false No definition available. No authoritative reference available. false 9 Deferred income taxes and investment tax credits, net 5 us-gaap_DeferredIncomeTaxesAndTaxCredits us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 220000000 220 false false 2 false true 411000000 411 false false 3 false true 177000000 177 false false No definition available. No authoritative reference available. false 10 Deferred fuel cost (credit) 5 pgn_DeferredFuelCostCredit pgn false debit duration monetary The net amount of capitalized fuel costs of a regulated entity that are expected to be recoverable through rate adjustments. false false false false false false false false false 1 false true 290000000 290 false false 2 false true -333000000 -333 false false 3 false true 117000000 117 false false The net amount of capitalized fuel costs of a regulated entity that are expected to be recoverable through rate adjustments. No authoritative reference available. false 11 Deferred income 5 us-gaap_RecognitionOfDeferredRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false 3 false true -128000000 -128 false false No definition available. No authoritative reference available. false 12 Allowance for equity funds used during construction 5 pgn_AllowanceForEquityFundsUsedDuringConstruction pgn false credit duration monetary The adjustment that is the result of a component of the allowance for funds used during construction during the period based... false false false false false false false false false 1 false true -124000000 -124 false false 2 false true -122000000 -122 false false 3 false true -51000000 -51 false false The adjustment that is the result of a component of the allowance for funds used during construction during the period based on an assumed rate of return on equity funds used in financing the construction of regulated assets. As a result of this capitalization, net income is increased. When calculating net cash generated by operating activities, this adjustment must be backed out of net income. No authoritative reference available. false 13 Loss (gain) on sales of assets 5 pgn_GainLossOnSaleOfAssets pgn false credit duration monetary The difference between the sale price and the book value of an asset that was sold during the reporting period. This element... false false false false false false false false false 1 false true 2000000 2 false false 2 false true -75000000 -75 false false 3 false true -29000000 -29 false false The difference between the sale price and the book value of an asset that was sold during the reporting period. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. No authoritative reference available. false 14 Other adjustments to net income 5 us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 269000000 269 false false 2 false true 135000000 135 false false 3 false true 212000000 212 false false No definition available. No authoritative reference available. false 15 Cash provided (used) by changes in operating assets and liabilities 5 us-gaap_IncreaseDecreaseInOperatingCapitalAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 16 Receivables 6 us-gaap_IncreaseDecreaseInReceivables us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 26000000 26 false false 2 false true 233000000 233 false false 3 false true -186000000 -186 false false No definition available. No authoritative reference available. false 17 Inventory 6 us-gaap_IncreaseDecreaseInInventories us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -99000000 -99 false false 2 false true -237000000 -237 false false 3 false true -11000000 -11 false false No definition available. No authoritative reference available. false 18 Derivative collateral posted 6 pgn_IncreaseDecreaseInDerivativeCollateralPosted pgn false credit duration monetary The net change during the reporting period in the amount of cash collateral posted for derivative instruments in a net... false false false false false false false false false 1 false true 200000000 200 false false 2 false true -340000000 -340 false false 3 false true 55000000 55 false false The net change during the reporting period in the amount of cash collateral posted for derivative instruments in a net liability position. No authoritative reference available. false 19 Prepayments and other current assets 6 pgn_IncreaseDecreaseInOtherCurrentOperatingAssets pgn false credit duration monetary The net change during the reporting period in other current operating assets not otherwise defined in the taxonomy. false false false false false false false false false 1 false true 3000000 3 false false 2 false true 7000000 7 false false 3 false true 35000000 35 false false The net change during the reporting period in other current operating assets not otherwise defined in the taxonomy. No authoritative reference available. false 20 Income taxes, net 6 pgn_CashUsedProvidedByChangesInIncomeTaxesNet pgn false credit duration monetary The net change during the period in the amount of current cash payments due to taxing authorities and due from taxing... false false false false false false false false false 1 false true -14000000 -14 false false 2 false true -169000000 -169 false false 3 false true -275000000 -275 false false The net change during the period in the amount of current cash payments due to taxing authorities and due from taxing authorities for taxes that are based on the reporting entity's earnings. No authoritative reference available. false 21 Accounts payable 6 us-gaap_IncreaseDecreaseInAccountsPayable us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -26000000 -26 false false 2 false true 77000000 77 false false 3 false true -40000000 -40 false false No definition available. No authoritative reference available. false 22 Other current liabilities 6 pgn_IncreaseDecreaseInOtherCurrentOperatingLiabilities pgn false debit duration monetary The net change during the reporting period in other current operating liabilities not otherwise defined in the taxonomy. false false false false false false false false false 1 false true -42000000 -42 false false 2 false true -103000000 -103 false false 3 false true 81000000 81 false false The net change during the reporting period in other current operating liabilities not otherwise defined in the taxonomy. No authoritative reference available. false 23 Other assets and deferred debits 6 pgn_IncreaseDecreaseInOtherNoncurrentOperatingAssets pgn false credit duration monetary The net change during the reporting period in other noncurrent operating assets not otherwise defined in the taxonomy. false false false false false false false false false 1 false true 11000000 11 false false 2 false true -44000000 -44 false false 3 false true -198000000 -198 false false The net change during the reporting period in other noncurrent operating assets not otherwise defined in the taxonomy. No authoritative reference available. false 24 Accrued pension and other benefits 6 pgn_Increasedecreaseinnoncurrentpensionandpostretirementobligations pgn false debit duration monetary The net change during the reporting period in the noncurrent amount due to fund pension and non-pension benefits to... false false false false false false false false false 1 false true -285000000 -285 false false 2 false true -39000000 -39 false false 3 false true -91000000 -91 false false The net change during the reporting period in the noncurrent amount due to fund pension and non-pension benefits to employees, retired and disabled former employees. No authoritative reference available. false 25 Other liabilities and deferred credits 6 pgn_IncreaseDecreaseInOtherNoncurrentOperatingLiabilities pgn false debit duration monetary The net change during the reporting period in other noncurrent operating liabilities not otherwise defined in the taxonomy. false false false false false false false false false 1 false true -56000000 -56 false false 2 false true 24000000 24 false false 3 false true 62000000 62 false false The net change during the reporting period in other noncurrent operating liabilities not otherwise defined in the taxonomy. No authoritative reference available. false 26 Net cash provided by operating activities 4 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true 2271000000 2271 false false 2 false true 1218000000 1218 false false 3 false true 1252000000 1252 false false No definition available. No authoritative reference available. true 27 Investing activities 3 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 28 Gross property additions 4 us-gaap_PaymentsToAcquirePropertyPlantAndEquipment us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -2295000000 -2295 false false 2 false true -2333000000 -2333 false false 3 false true -1973000000 -1973 false false No definition available. No authoritative reference available. false 29 Nuclear fuel additions 4 us-gaap_PaymentsForProceedsFromNuclearFuel us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -200000000 -200 false false 2 false true -222000000 -222 false false 3 false true -228000000 -228 false false No definition available. No authoritative reference available. false 30 Proceeds from sales of discontinued operations and other assets, net of cash divested 4 pgn_ProceedsFromSalesOfDiscontinuedOperationsAndOtherAssetsNetOfCashDivested pgn false debit duration monetary The cash inflow from the sales of discontinued operations and other assets not otherwise defined in the taxonomy, net of cash... false false false false false false false false false 1 false true 1000000 1 false false 2 false true 72000000 72 false false 3 false true 675000000 675 false false The cash inflow from the sales of discontinued operations and other assets not otherwise defined in the taxonomy, net of cash divested. No authoritative reference available. false 31 Purchases of available-for-sale securities and other investments 4 us-gaap_PaymentsToAcquireInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -2350000000 -2350 false false 2 false true -1590000000 -1590 false false 3 false true -1413000000 -1413 false false No definition available. No authoritative reference available. false 32 Proceeds from available-for-sale securities and other investments 4 us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 2314000000 2314 false false 2 false true 1534000000 1534 false false 3 false true 1452000000 1452 false false No definition available. No authoritative reference available. false 33 Other investing activities 4 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -2000000 -2 false false 2 false true -2000000 -2 false false 3 false true 30000000 30 false false No definition available. No authoritative reference available. false 34 Net cash used by investing activities 4 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -2532000000 -2532 false false 2 false true -2541000000 -2541 false false 3 false true -1457000000 -1457 false false No definition available. No authoritative reference available. true 35 Financing activities 3 us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 36 Issuance of common stock 4 us-gaap_ProceedsFromIssuanceOfCommonStock us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 623000000 623 false false 2 false true 132000000 132 false false 3 false true 151000000 151 false false No definition available. No authoritative reference available. false 37 Dividends paid on common stock 4 us-gaap_PaymentsOfDividendsCommonStock us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -693000000 -693 false false 2 false true -642000000 -642 false false 3 false true -627000000 -627 false false No definition available. No authoritative reference available. false 38 Payments of short-term debt with original maturities greater than 90 days 4 us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -29000000 -29 false false 2 false true -176000000 -176 false false 3 false true 0 0 false false No definition available. No authoritative reference available. false 39 Proceeds from issuance of short-term debt with original maturities greater than 90 days 4 us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 29000000 29 false false 3 false true 176000000 176 false false No definition available. No authoritative reference available. false 40 Net (decrease) increase in short-term debt 4 us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -981000000 -981 false false 2 false true 1096000000 1096 false false 3 false true 25000000 25 false false No definition available. No authoritative reference available. false 41 Proceeds from issuance of long-term debt, net 4 us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 2278000000 2278 false false 2 false true 1797000000 1797 false false 3 false true 739000000 739 false false No definition available. No authoritative reference available. false 42 Retirement of long-term debt 4 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -400000000 -400 false false 2 false true -877000000 -877 false false 3 false true -324000000 -324 false false No definition available. No authoritative reference available. false 43 Cash distributions to noncontrolling interests 4 pgn_CashDistributionsToNoncontrollingInterestsOfConsolidatedSubsidiaries pgn false credit duration monetary The cash outflow to noncontrolled interests that represent returns of capital and returns on capital. false false false false false false false false false 1 false true -6000000 -6 false false 2 false true -85000000 -85 false false 3 false true -10000000 -10 false false The cash outflow to noncontrolled interests that represent returns of capital and returns on capital. No authoritative reference available. false 44 Other financing activities 4 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 14000000 14 false false 2 false true -26000000 -26 false false 3 false true 65000000 65 false false No definition available. No authoritative reference available. false 45 Net cash provided by financing activities 4 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 806000000 806 false false 2 false true 1248000000 1248 false false 3 false true 195000000 195 false false No definition available. No authoritative reference available. true 46 Net increase (decrease) in cash and cash equivalents 3 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true 545000000 545 false false 2 false true -75000000 -75 false false 3 false true -10000000 -10 false false No definition available. No authoritative reference available. true 47 Cash and cash equivalents at beginning of year 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false true false false 1 false true 180000000 180 false false 2 false true 255000000 255 false false 3 false true 265000000 265 false false No definition available. No authoritative reference available. false 48 Cash and cash equivalents at end of year 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false true false 1 false true 725000000 725 false false 2 false true 180000000 180 false false 3 false true 255000000 255 false false No definition available. No authoritative reference available. false 50 Cash paid during the year 4 pgn_Cashpaidduringtheyearabstract pgn false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 51 Interest, net of amount capitalized 5 us-gaap_InterestPaidNet us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 701000000 701 false false 2 false true 612000000 612 false false 3 false true 585000000 585 false false No definition available. No authoritative reference available. false 52 Income taxes, net of refunds 5 us-gaap_IncomeTaxesPaidNet us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 87000000 87 false false 2 false true 152000000 152 false false 3 false true 176000000 176 false false No definition available. No authoritative reference available. false 53 Significant noncash transactions 4 pgn_SignificantNoncashTransactionsAbstract pgn false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 54 Capital lease obligation incurred 5 us-gaap_CapitalLeaseObligationsIncurred us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false 3 false true 182000000 182 false false No definition available. No authoritative reference available. false 55 Accrued property additions 5 us-gaap_CapitalExpendituresIncurredButNotYetPaid us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 252000000 252 false false 2 false true 334000000 334 false false 3 false true 329000000 329 false false No definition available. No authoritative reference available. false 56 Asset retirement obligation additions and estimate revisions 5 pgn_Assetretirementobligationadditionsandestimaterevisions pgn false credit duration monetary The amount of asset retirement obligations incurred and the increase (decrease) to asset retirement obligations due to the... false false false false false false false false false 1 true true -384000000 -384 false false 2 true true 14000000 14 false false 3 true true 0 0 false false The amount of asset retirement obligations incurred and the increase (decrease) to asset retirement obligations due to the revisions of prior estimates during the period. No authoritative reference available. false false 3 51 false Millions UnKnown UnKnown false true