2.2.0.7 false CONSOLIDATED INCOME STATEMENTS (Unaudited) (USD $) 001000 - Statement - CONSOLIDATED INCOME STATEMENTS (Unaudited) true false In Thousands, except Share data false false 1 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false u000 Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 u002 Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 u001 Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Income Statement [Abstract] 0 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 3 OPERATING REVENUES 1 us-gaap_RegulatedOperatingRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 true true false false 1131561000 1131561 false false false 2 true true false false 1219007000 1219007 false false false 3 true true false false 2633891000 2633891 false false false 4 true true false false 2812915000 2812915 false false false xbrli:monetaryItemType monetary The total amount of regulated operating revenues recognized during the period. No authoritative reference available. true 4 OPERATING EXPENSES: 1 us-gaap_OperatingExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 5 Fuel for power generation 2 us-gaap_ElectricProductionExpense us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 247233000 247233 false false false 2 false true false false 250085000 250085 false false false 3 false true false false 650514000 650514 false false false 4 false true false false 684474000 684474 false false false xbrli:monetaryItemType monetary Cost incurred directly related to electricity produced and sold during the reporting period. 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No authoritative reference available. false 8 Deferred energy 2 nve_DeferralOfEnergyCostElectricNet nve false debit duration Represent the difference between actual fuel and purchased power costs incurred during the period and amounts recoverable... false false false false false false false false false false false terselabel false 1 false true false false 34055000 34055 false false false 2 false true false false 75843000 75843 false false false 3 false true false false 106554000 106554 false false false 4 false true false false 215055000 215055 false false false xbrli:monetaryItemType monetary Represent the difference between actual fuel and purchased power costs incurred during the period and amounts recoverable through currents rates. Also includes the current amortization of fuel and purchased power costs previously deferred. No authoritative reference available. false 9 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 116263000 116263 false false false 2 false true false false 107992000 107992 false false false 3 false true false false 329435000 329435 false false false 4 false true false false 332555000 332555 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 10 Maintenance 2 us-gaap_UtilitiesOperatingExpenseMaintenance us-gaap true debit duration No definition available. false false false false false false false false false false false false 1 false true false false 23126000 23126 false false false 2 false true false false 20187000 20187 false false false 3 false true false false 77715000 77715 false false false 4 false true false false 82219000 82219 false false false xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period for routine plant maintenance and repairs. 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No authoritative reference available. false 13 Total Operating Expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 780197000 780197 false false false 2 false true false false 876922000 876922 false false false 3 false true false false 2084891000 2084891 false false false 4 false true false false 2334434000 2334434 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 14 OPERATING INCOME 1 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 351364000 351364 false false false 2 false true false false 342085000 342085 false false false 3 false true false false 549000000 549000 false false false 4 false true false false 478481000 478481 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 15 OTHER INCOME (EXPENSE): 1 us-gaap_OtherNonoperatingIncomeExpenseAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 16 Interest expense (net of AFUDC-debt: $6,485, $3,679, $17,349 and $15,847) 2 nve_InterestExpenseNetOfAfudc nve false credit duration The cost of borrowed funds accounted for as interest that was charged against earnings during the period, net of any... false false false false false false false false false false false terselabel false 1 false true false false -80789000 -80789 false false false 2 false true false false -84804000 -84804 false false false 3 false true false false -241625000 -241625 false false false 4 false true false false -250996000 -250996 false false false xbrli:monetaryItemType monetary The cost of borrowed funds accounted for as interest that was charged against earnings during the period, net of any capitalized interest amounts. No authoritative reference available. false 17 Interest income (expense) on regulatory items 2 nve_InterestIncomeExpenseOnRegulatoryItems nve false credit duration Interest income or expense on regulatory items; including carrying charges on assets and interest accrued on deferred energy... false false false false false false false false false false false terselabel false 1 false true false false -3685000 -3685 false false false 2 false true false false -1799000 -1799 false false false 3 false true false false -8753000 -8753 false false false 4 false true false false -873000 -873 false false false xbrli:monetaryItemType monetary Interest income or expense on regulatory items; including carrying charges on assets and interest accrued on deferred energy balance No authoritative reference available. false 18 AFUDC-equity 2 nve_AllowanceForEquityFundsUsedDuringConstruction nve false credit duration Total increase in earnings in the period representing the cost of equity (rate of return) used to finance construction of... false false false false false false false false false false false terselabel false 1 false true false false 7824000 7824 false false false 2 false true false false 4327000 4327 false false false 3 false true false false 20915000 20915 false false false 4 false true false false 19093000 19093 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. No authoritative reference available. false 19 Other income 2 us-gaap_OtherIncome us-gaap true credit duration No definition available. false false false false false false false false false false false false 1 false true false false 9246000 9246 false false false 2 false true false false 7749000 7749 false false false 3 false true false false 30524000 30524 false false false 4 false true false false 31209000 31209 false false false xbrli:monetaryItemType monetary Reflects the sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement. 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