1.0.0.3 false CONSOLIDATED STATEMENTS of INCOME (USD $) In Millions, except Per Share data 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 revenues 3 us-gaap_UtilityRevenue us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 9885000000 9885 false false 2 true true 9167000000 9167 false false 3 true true 9153000000 9153 false false No definition available. No authoritative reference available. false 6 Operating expenses 3 us-gaap_OperatingExpensesAbstract 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 7 Fuel used in electric generation 4 us-gaap_FuelCosts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3752000000 3752 false false 2 false true 3021000000 3021 false false 3 false true 3145000000 3145 false false No definition available. No authoritative reference available. false 8 Purchased power 4 us-gaap_CostOfPurchasedPower us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 911000000 911 false false 2 false true 1299000000 1299 false false 3 false true 1184000000 1184 false false No definition available. No authoritative reference available. false 9 Operation and maintenance 4 pgn_OperatingMaintenanceExpense pgn false debit duration monetary The amount of operating expense for the period for maintenance, repairs and operations. false false false false false false false false false 1 false true 1894000000 1894 false false 2 false true 1820000000 1820 false false 3 false true 1842000000 1842 false false The amount of operating expense for the period for maintenance, repairs and operations. No authoritative reference available. false 10 Depreciation, amortization and accretion 4 pgn_DepreciationAmortizationAndAccretion pgn false debit duration monetary The current period expense charged against earnings on long-lived, physical assets used in the normal conduct of business and... false false false false false false false false false 1 false true 986000000 986 false false 2 false true 839000000 839 false false 3 false true 905000000 905 false false The current period expense charged against earnings on long-lived, physical assets used in the normal conduct of business and not intended for resale to allocate or recognize the cost of assets over their useful lives; to record the reduction in book value of an intangible asset over the benefit period of such asset; or to record accretion expense in each subsequent period to recognize asset or liability growth resulting from the passage of time. No authoritative reference available. false 11 Taxes other than on income 4 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 557000000 557 false false 2 false true 508000000 508 false false 3 false true 501000000 501 false false No definition available. No authoritative reference available. false 12 Other 4 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 13000000 13 false false 2 false true -3000000 -3 false false 3 false true 30000000 30 false false No definition available. No authoritative reference available. false 13 Total operating expenses 4 us-gaap_CostsAndExpenses us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 8113000000 8113 false false 2 false true 7484000000 7484 false false 3 false true 7607000000 7607 false false No definition available. No authoritative reference available. true 14 Operating income 3 us-gaap_OperatingIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1772000000 1772 false false 2 false true 1683000000 1683 false false 3 false true 1546000000 1546 false false No definition available. No authoritative reference available. true 15 Other income (expense) 3 us-gaap_NonoperatingIncomeExpenseAbstract 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 Interest income 4 pgn_InterestAndDividendIncome pgn false credit duration monetary Includes all interest income, including impacts of discount accretion and premium amortization, and dividend income. false false false false false false false false false 1 false true 14000000 14 false false 2 false true 24000000 24 false false 3 false true 34000000 34 false false Includes all interest income, including impacts of discount accretion and premium amortization, and dividend income. No authoritative reference available. false 17 Allowance for equity funds used during construction 4 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity us-gaap true credit duration monetary No definition available. 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 No definition available. No authoritative reference available. false 18 Other, net 4 us-gaap_OtherNonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 6000000 6 false false 2 false true -17000000 -17 false false 3 false true -7000000 -7 false false No definition available. No authoritative reference available. false 19 Total other income, net 4 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 144000000 144 false false 2 false true 129000000 129 false false 3 false true 78000000 78 false false No definition available. No authoritative reference available. true 20 Interest charges 3 us-gaap_InterestAndDebtExpenseAbstract 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 21 Interest charges 4 us-gaap_InterestExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 718000000 718 false false 2 false true 679000000 679 false false 3 false true 605000000 605 false false No definition available. No authoritative reference available. false 22 Allowance for borrowed funds used during construction 4 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -39000000 -39 false false 2 false true -40000000 -40 false false 3 false true -17000000 -17 false false No definition available. No authoritative reference available. false 23 Total interest charges, net 4 us-gaap_InterestAndDebtExpense us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 679000000 679 false false 2 false true 639000000 639 false false 3 false true 588000000 588 false false No definition available. No authoritative reference available. false 24 Income from continuing operations before income tax 3 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1237000000 1237 false false 2 false true 1173000000 1173 false false 3 false true 1036000000 1036 false false No definition available. No authoritative reference available. false 25 Income tax expense 3 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 397000000 397 false false 2 false true 395000000 395 false false 3 false true 334000000 334 false false No definition available. No authoritative reference available. false 26 Income from continuing operations 3 us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 840000000 840 false false 2 false true 778000000 778 false false 3 false true 702000000 702 false false No definition available. No authoritative reference available. true 27 Discontinued operations, net of tax 3 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -79000000 -79 false false 2 false true 58000000 58 false false 3 false true -206000000 -206 false false No definition available. No authoritative reference available. false 28 Net income 3 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 761000000 761 false false 2 false true 836000000 836 false false 3 false true 496000000 496 false false No definition available. No authoritative reference available. false 29 Net (income) loss attributable to noncontrolling interests, net of tax 3 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -4000000 -4 false false 2 false true -6000000 -6 false false 3 false true 8000000 8 false false No definition available. No authoritative reference available. false 30 Net income attributable to controlling interests 3 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 757000000 757 false false 2 false true 830000000 830 false false 3 false true 504000000 504 false false No definition available. No authoritative reference available. false 31 Average common shares outstanding - basic 3 us-gaap_WeightedAverageNumberOfSharesOutstandingBasic us-gaap true na duration shares No definition available. false false false false false false false false false 1 false true 279000000 279 false false 2 false true 262000000 262 false false 3 false true 257000000 257 false false No definition available. No authoritative reference available. false 33 Earnings Per Share Basic, [Abstract] 4 us-gaap_EarningsPerShareBasicAbstract 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 34 Income from continuing operations attributable to controlling interests, net of tax 5 us-gaap_IncomeLossFromContinuingOperationsPerBasicShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 2.99 2.99 false false 2 true true 2.95 2.95 false false 3 true true 2.70 2.70 false false No definition available. No authoritative reference available. false 35 Discontinued operations attributable to controlling interests, net of tax 5 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true -0.28 -0.28 false false 2 true true 0.22 0.22 false false 3 true true -0.74 -0.74 false false No definition available. No authoritative reference available. false 36 Net income attributable to controlling interests 5 us-gaap_EarningsPerShareBasic us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 2.71 2.71 false false 2 true true 3.17 3.17 false false 3 true true 1.96 1.96 false false No definition available. No authoritative reference available. true 37 Earnings Per Share, Diluted [Abstract] 4 us-gaap_EarningsPerShareDilutedAbstract 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 38 Income from continuing operations attributable to controlling interests, net of tax 5 us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 2.99 2.99 false false 2 true true 2.95 2.95 false false 3 true true 2.70 2.70 false false No definition available. No authoritative reference available. false 39 Discontinued operations attributable to controlling interests, net of tax 5 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true -0.28 -0.28 false false 2 true true 0.22 0.22 false false 3 true true -0.74 -0.74 false false No definition available. No authoritative reference available. false 40 Net income attributable to controlling interests 5 us-gaap_EarningsPerShareDiluted us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 2.71 2.71 false false 2 true true 3.17 3.17 false false 3 true true 1.96 1.96 false false No definition available. No authoritative reference available. true 41 Dividends per share 3 us-gaap_CommonStockDividendsPerShareDeclared us-gaap true na duration decimal No definition available. false false false false false false false false true 1 true true 2.480 2.480 false false 2 true true 2.465 2.465 false false 3 true true 2.445 2.445 false false No definition available. No authoritative reference available. false 42 Amounts attributable to controlling interests 3 us-gaap_IncomeAmountsAttributableToReportingEntityDisclosuresAbstract 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 43 Income from continuing operations attributable to controlling interests, net of tax 4 us-gaap_IncomeLossFromContinuingOperations us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 836000000 836 false false 2 false true 773000000 773 false false 3 false true 693000000 693 false false No definition available. No authoritative reference available. false 44 Discontinued operations attributable to controlling interests, net of tax 4 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -79000000 -79 false false 2 false true 57000000 57 false false 3 false true -189000000 -189 false false No definition available. No authoritative reference available. false 45 Net income attributable to controlling interests 4 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 757000000 757 false false 2 true true 830000000 830 false false 3 true true 504000000 504 false false No definition available. No authoritative reference available. false false 3 40 false Millions Millions NoRounding false true