10-K Filing

SOUTHWEST GAS CORP CIK: 92416 FY 2013

Filing Information

Form Type	10-K
Accession Number	`0001193125-14-072142`
Period End Date	20131231
Filing Date	20140227
Fiscal Year	2013
Fiscal Period	FY
XBRL Instance	swx-20131231.xml

Filing Contents

This filing contains the following financial statements:

Balance Sheet 92 Income Statement 138 Cash Flow Statement 110 Stockholders Equity 49 Comprehensive Income 51

Balance Sheet 92 line items

Line Item	Tag	Value	Unit	Period
Common stock, par	`CommonStockParOrStatedValuePerShare`	$1.00	USD	Point-in-time
Common stock, par	`CommonStockParOrStatedValuePerShare`	$1.00	USD	Point-in-time
Common stock, authorized	`CommonStockSharesAuthorized`	60.00M	shares	Point-in-time
Common stock, authorized	`CommonStockSharesAuthorized`	60.00M	shares	Point-in-time
Common stock, issued	`CommonStockSharesIssued`	46.15M	shares	Point-in-time
Common stock, issued	`CommonStockSharesIssued`	46.36M	shares	Point-in-time
Gas plant	`PublicUtilitiesPropertyPlantAndEquipmentPlantInService`	$5.25B	USD	Point-in-time
Gas plant	`PublicUtilitiesPropertyPlantAndEquipmentPlantInService`	$5.02B	USD	Point-in-time
Less: accumulated depreciation	`PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation`	$1.87B	USD	Point-in-time
Common stock, outstanding	`CommonStockSharesOutstanding`	46.36M	shares	Point-in-time
Common stock, outstanding	`CommonStockSharesOutstanding`	46.15M	shares	Point-in-time
Less: accumulated depreciation	`PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation`	$1.75B	USD	Point-in-time
Acquisition adjustments, net	`PublicUtilitiesPropertyPlantAndEquipmentAmountOfAcquisitionAdjustments1`	$730.00K	USD	Point-in-time
Acquisition adjustments, net	`PublicUtilitiesPropertyPlantAndEquipmentAmountOfAcquisitionAdjustments1`	$911.00K	USD	Point-in-time
Construction work in progress	`PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress`	$101.41M	USD	Point-in-time
Construction work in progress	`PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress`	$74.18M	USD	Point-in-time
Net utility plant (Note 2)	`PublicUtilitiesPropertyPlantAndEquipmentNet`	$3.34B	USD	Point-in-time
Net utility plant (Note 2)	`PublicUtilitiesPropertyPlantAndEquipmentNet`	$3.49B	USD	Point-in-time
Other property and investments (Note 1)	`OtherPropertyAndInvestments`	$242.10M	USD	Point-in-time
Other property and investments (Note 1)	`OtherPropertyAndInvestments`	$260.87M	USD	Point-in-time
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$116.10M	USD	Point-in-time
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$21.94M	USD	Point-in-time
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$25.53M	USD	Point-in-time
Cash and cash equivalents	`CashAndCashEquivalentsAtCarryingValue`	$41.08M	USD	Point-in-time
Accounts receivable, net of allowances (Note 3)	`AccountsReceivableNetCurrent`	$196.91M	USD	Point-in-time
Accounts receivable, net of allowances (Note 3)	`AccountsReceivableNetCurrent`	$219.47M	USD	Point-in-time
Accrued utility revenue	`OtherReceivables`	$72.00M	USD	Point-in-time
Accrued utility revenue	`OtherReceivables`	$72.70M	USD	Point-in-time
Income taxes receivable, net	`IncomeTaxesReceivable`	$3.79M	USD	Point-in-time
Income taxes receivable, net	`IncomeTaxesReceivable`	$2.94M	USD	Point-in-time
Deferred income taxes (Note 11)	`DeferredTaxAssetsNetCurrent`	$31.13M	USD	Point-in-time
Deferred income taxes (Note 11)	`DeferredTaxAssetsNetCurrent`	$47.09M	USD	Point-in-time
Deferred purchased gas costs (Note 4)	`DeferredGasCost`	$6.03M	USD	Point-in-time
Deferred purchased gas costs (Note 4)	`DeferredGasCost`	$18.22M	USD	Point-in-time
Prepaids and other current assets (Notes 1, 4, and 12)	`PrepaidExpenseAndOtherAssetsCurrent`	$107.91M	USD	Point-in-time
Prepaids and other current assets (Notes 1, 4, and 12)	`PrepaidExpenseAndOtherAssetsCurrent`	$108.29M	USD	Point-in-time
Total current assets	`AssetsCurrent`	$458.42M	USD	Point-in-time
Total current assets	`AssetsCurrent`	$494.67M	USD	Point-in-time
Deferred charges and other assets (Notes 4 and 12)	`OtherAssetsNoncurrent`	$323.52M	USD	Point-in-time
Deferred charges and other assets (Notes 4 and 12)	`OtherAssetsNoncurrent`	$443.75M	USD	Point-in-time
Total assets	`Assets`	$4.57B	USD	Point-in-time
Total assets	`Assets`	$4.28B	USD	Point-in-time
Total assets	`Assets`	$4.49B	USD	Point-in-time
Common stock, $1 par (authorized - 60,000,000 shares; issued and outstanding - 46,356,125 and 46,147,788 shares) (Note 10)	`CommonStockValue`	$47.78M	USD	Point-in-time
Common stock, $1 par (authorized - 60,000,000 shares; issued and outstanding - 46,356,125 and 46,147,788 shares) (Note 10)	`CommonStockValue`	$47.99M	USD	Point-in-time
Additional paid-in capital	`AdditionalPaidInCapitalCommonStock`	$840.52M	USD	Point-in-time
Additional paid-in capital	`AdditionalPaidInCapitalCommonStock`	$828.78M	USD	Point-in-time
Accumulated other comprehensive income (loss), net (Note 5)	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-41.70M	USD	Point-in-time
Accumulated other comprehensive income (loss), net (Note 5)	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-50.74M	USD	Point-in-time
Retained earnings	`RetainedEarningsAccumulatedDeficit`	$484.37M	USD	Point-in-time
Retained earnings	`RetainedEarningsAccumulatedDeficit`	$567.71M	USD	Point-in-time
Total Southwest Gas Corporation equity	`StockholdersEquity`	$1.31B	USD	Point-in-time
Total Southwest Gas Corporation equity	`StockholdersEquity`	$1.41B	USD	Point-in-time
Noncontrolling interest	`MinorityInterest`	$-1.68M	USD	Point-in-time
Noncontrolling interest	`MinorityInterest`	$-2.13M	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.31B	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.23B	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.41B	USD	Point-in-time
Total equity	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.17B	USD	Point-in-time
Long-term debt, less current maturities (Note 6)	`LongTermDebtNoncurrent`	$1.38B	USD	Point-in-time
Long-term debt, less current maturities (Note 6)	`LongTermDebtNoncurrent`	$1.27B	USD	Point-in-time
Total capitalization	`CapitalizationLongtermDebtAndEquity`	$2.58B	USD	Point-in-time
Total capitalization	`CapitalizationLongtermDebtAndEquity`	$2.79B	USD	Point-in-time
Commitments and contingencies (Note 8)	`CommitmentsAndContingencies`	-	USD	Point-in-time
Commitments and contingencies (Note 8)	`CommitmentsAndContingencies`	-	USD	Point-in-time
Current maturities of long-term debt (Note 6)	`LongTermDebtCurrent`	$50.14M	USD	Point-in-time
Current maturities of long-term debt (Note 6)	`LongTermDebtCurrent`	$11.11M	USD	Point-in-time
Accounts payable	`AccountsPayableCurrent`	$155.67M	USD	Point-in-time
Accounts payable	`AccountsPayableCurrent`	$183.51M	USD	Point-in-time
Customer deposits	`CustomerDepositsCurrent`	$77.86M	USD	Point-in-time
Customer deposits	`CustomerDepositsCurrent`	$73.37M	USD	Point-in-time
Accrued general taxes	`AccrualForTaxesOtherThanIncomeTaxesCurrent`	$37.64M	USD	Point-in-time
Accrued general taxes	`AccrualForTaxesOtherThanIncomeTaxesCurrent`	$39.68M	USD	Point-in-time
Accrued interest	`InterestPayableCurrent`	$17.92M	USD	Point-in-time
Accrued interest	`InterestPayableCurrent`	$16.08M	USD	Point-in-time
Deferred purchased gas costs (Note 4)	`RefundableGasCosts`	$98.96M	USD	Point-in-time
Other current liabilities (Notes 4 and 12)	`OtherLiabilitiesCurrent`	$108.58M	USD	Point-in-time
Other current liabilities (Notes 4 and 12)	`OtherLiabilitiesCurrent`	$98.79M	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$434.16M	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$535.13M	USD	Point-in-time
Deferred income taxes and investment tax credits (Note 11)	`DeferredIncomeTaxesAndUnamortizedInvestmentTaxCredits`	$674.41M	USD	Point-in-time
Deferred income taxes and investment tax credits (Note 11)	`DeferredIncomeTaxesAndUnamortizedInvestmentTaxCredits`	$616.18M	USD	Point-in-time
Taxes payable	`TaxesPayableNoncurrent`	$284.00K	USD	Point-in-time
Taxes payable	`TaxesPayableNoncurrent`	$551.00K	USD	Point-in-time
Accumulated removal costs (Note 4)	`OtherAccruedLiabilitiesNoncurrent`	$256.00M	USD	Point-in-time
Accumulated removal costs (Note 4)	`OtherAccruedLiabilitiesNoncurrent`	$279.00M	USD	Point-in-time
Other deferred credits (Notes 4, 9, and 12)	`OtherDeferredCreditsNoncurrent`	$503.32M	USD	Point-in-time
Other deferred credits (Notes 4, 9, and 12)	`OtherDeferredCreditsNoncurrent`	$383.59M	USD	Point-in-time
Total deferred income taxes and other credits	`OtherLiabilitiesNoncurrent`	$1.34B	USD	Point-in-time
Total deferred income taxes and other credits	`OtherLiabilitiesNoncurrent`	$1.38B	USD	Point-in-time
Total capitalization and liabilities	`LiabilitiesAndStockholdersEquity`	$4.57B	USD	Point-in-time
Total capitalization and liabilities	`LiabilitiesAndStockholdersEquity`	$4.49B	USD	Point-in-time

Income Statement 138 line items

Line Item	Tag	Value	Unit	Period
Gas operating revenues	`RegulatedOperatingRevenueGas`	$1.32B	USD	Annual
Gas operating revenues	`RegulatedOperatingRevenueGas`	$1.30B	USD	Annual
Gas operating revenues	`RegulatedOperatingRevenueGas`	$1.40B	USD	Annual
Construction revenues	`ConstructionRevenue`	$483.82M	USD	Annual
Construction revenues	`ConstructionRevenue`	$650.63M	USD	Annual
Construction revenues	`ConstructionRevenue`	$606.05M	USD	Annual
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$1.93B	USD	Annual
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$628.44M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$1.89B	USD	Annual
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$657.64M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$388.50M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$411.57M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$613.50M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$371.80M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$517.65M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$538.36M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$1.95B	USD	Annual
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$488.57M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$352.59M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$409.77M	USD	1 Quarter
Total operating revenues	`RegulatedAndUnregulatedOperatingRevenue`	$387.35M	USD	1 Quarter
Net cost of gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$479.60M	USD	Annual
Net cost of gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$613.49M	USD	Annual
Net cost of gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$436.00M	USD	Annual
Operations and maintenance	`UtilitiesOperatingExpenseMaintenanceAndOperations`	$369.98M	USD	Annual
Operations and maintenance	`UtilitiesOperatingExpenseMaintenanceAndOperations`	$384.91M	USD	Annual
Operations and maintenance	`UtilitiesOperatingExpenseMaintenanceAndOperations`	$358.50M	USD	Annual
Depreciation and amortization	`DepreciationAndAmortization`	$223.42M	USD	Annual
Depreciation and amortization	`DepreciationAndAmortization`	$200.47M	USD	Annual
Depreciation and amortization	`DepreciationAndAmortization`	$236.82M	USD	Annual
Taxes other than income taxes	`TaxesExcludingIncomeAndExciseTaxes`	$41.73M	USD	Annual
Taxes other than income taxes	`TaxesExcludingIncomeAndExciseTaxes`	$45.55M	USD	Annual
Taxes other than income taxes	`TaxesExcludingIncomeAndExciseTaxes`	$40.95M	USD	Annual
Construction expenses	`ConstructionAndDevelopmentCosts`	$541.52M	USD	Annual
Construction expenses	`ConstructionAndDevelopmentCosts`	$423.70M	USD	Annual
Construction expenses	`ConstructionAndDevelopmentCosts`	$573.28M	USD	Annual
Total operating expenses	`CostsAndExpenses`	$1.64B	USD	Annual
Total operating expenses	`CostsAndExpenses`	$1.66B	USD	Annual
Total operating expenses	`CostsAndExpenses`	$1.68B	USD	Annual
Operating income	`OperatingIncomeLoss`	$101.92M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$6.14M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$274.21M	USD	Annual
Operating income	`OperatingIncomeLoss`	$20.57M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$271.52M	USD	Annual
Operating income	`OperatingIncomeLoss`	$138.39M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$126.33M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$1.25M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$115.21M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$28.91M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$6.31M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$134.62M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$100.77M	USD	1 Quarter
Operating income	`OperatingIncomeLoss`	$250.08M	USD	Annual
Operating income	`OperatingIncomeLoss`	$15.38M	USD	1 Quarter
Net interest deductions (Notes 6 and 7)	`InterestExpense`	$63.70M	USD	Annual
Net interest deductions (Notes 6 and 7)	`InterestExpense`	$69.60M	USD	Annual
Net interest deductions (Notes 6 and 7)	`InterestExpense`	$68.02M	USD	Annual
Other income (deductions)	`OtherNonoperatingIncomeExpense`	$12.30M	USD	Annual
Other income (deductions)	`OtherNonoperatingIncomeExpense`	$4.41M	USD	Annual
Other income (deductions)	`OtherNonoperatingIncomeExpense`	$-5.41M	USD	Annual
Total other income and (expenses)	`NonoperatingIncomeExpense`	$-63.61M	USD	Annual
Total other income and (expenses)	`NonoperatingIncomeExpense`	$-75.01M	USD	Annual
Total other income and (expenses)	`NonoperatingIncomeExpense`	$-51.40M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments`	$175.07M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments`	$222.81M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments`	$207.91M	USD	Annual
Income tax expense (Note 11)	`IncomeTaxExpenseBenefit`	$63.30M	USD	Annual
Income tax expense (Note 11)	`IncomeTaxExpenseBenefit`	$77.94M	USD	Annual
Income tax expense (Note 11)	`IncomeTaxExpenseBenefit`	$75.28M	USD	Annual
Net income	`ProfitLoss`	$57.19M	USD	1 Quarter
Net income	`ProfitLoss`	$-4.41M	USD	1 Quarter
Net income	`ProfitLoss`	$62.11M	USD	1 Quarter
Net income	`ProfitLoss`	$4.01M	USD	1 Quarter
Net income	`ProfitLoss`	$78.83M	USD	1 Quarter
Net income	`ProfitLoss`	$132.64M	USD	Annual
Net income	`ProfitLoss`	$80.67M	USD	1 Quarter
Net income	`ProfitLoss`	$55.14M	USD	1 Quarter
Net income	`ProfitLoss`	$-3.06M	USD	1 Quarter
Net income	`ProfitLoss`	$111.76M	USD	Annual
Net income	`ProfitLoss`	$144.87M	USD	Annual
Net income	`ProfitLoss`	$-3.89M	USD	1 Quarter
Net income	`ProfitLoss`	$68.35M	USD	1 Quarter
Net income	`ProfitLoss`	$-15.75M	USD	1 Quarter
Net income	`ProfitLoss`	$10.07M	USD	1 Quarter
Net income (loss) attributable to noncontrolling interest	`NetIncomeLossAttributableToNoncontrollingInterest`	$-524.00K	USD	Annual
Net income (loss) attributable to noncontrolling interest	`NetIncomeLossAttributableToNoncontrollingInterest`	$-447.00K	USD	Annual
Net income (loss) attributable to noncontrolling interest	`NetIncomeLossAttributableToNoncontrollingInterest`	$-692.00K	USD	Annual
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$-15.64M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$145.32M	USD	Annual
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$10.11M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$133.33M	USD	Annual
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$-2.86M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$112.29M	USD	Annual
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$-3.68M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$62.39M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$4.05M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$55.32M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$-4.30M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$68.55M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$78.92M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$80.77M	USD	1 Quarter
Net income attributable to Southwest Gas Corporation	`NetIncomeLoss`	$57.30M	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$3.14	USD	Annual
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$2.45	USD	Annual
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.20	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$0.22	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.71	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$-0.34	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.75	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.50	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$-0.06	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.24	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$2.89	USD	Annual
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$0.09	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$-0.08	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$-0.09	USD	1 Quarter
Basic earnings per share (Note 14)	`EarningsPerShareBasic`	$1.35	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$0.22	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.34	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$3.11	USD	Annual
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$2.43	USD	Annual
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.48	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$-0.08	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$2.86	USD	Annual
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$-0.34	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.19	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.73	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$-0.06	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.22	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$1.70	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$-0.09	USD	1 Quarter
Diluted earnings per share (Note 14)	`EarningsPerShareDiluted`	$0.09	USD	1 Quarter
Average number of common shares outstanding	`WeightedAverageNumberOfSharesOutstandingBasic`	46.32M	shares	Annual
Average number of common shares outstanding	`WeightedAverageNumberOfSharesOutstandingBasic`	45.86M	shares	Annual
Average number of common shares outstanding	`WeightedAverageNumberOfSharesOutstandingBasic`	46.12M	shares	Annual
Average shares outstanding (assuming dilution)	`WeightedAverageNumberOfDilutedSharesOutstanding`	46.76M	shares	Annual
Average shares outstanding (assuming dilution)	`WeightedAverageNumberOfDilutedSharesOutstanding`	46.29M	shares	Annual
Average shares outstanding (assuming dilution)	`WeightedAverageNumberOfDilutedSharesOutstanding`	46.55M	shares	Annual

Cash Flow Statement 110 line items

Line Item	Tag	Value	Unit	Period
Net Income	`ProfitLoss`	$-15.75M	USD	1 Quarter
Net Income	`ProfitLoss`	$-4.41M	USD	1 Quarter
Net Income	`ProfitLoss`	$4.01M	USD	1 Quarter
Net Income	`ProfitLoss`	$57.19M	USD	1 Quarter
Net Income	`ProfitLoss`	$78.83M	USD	1 Quarter
Net Income	`ProfitLoss`	$55.14M	USD	1 Quarter
Net Income	`ProfitLoss`	$132.64M	USD	Annual
Net Income	`ProfitLoss`	$62.11M	USD	1 Quarter
Net Income	`ProfitLoss`	$10.07M	USD	1 Quarter
Net Income	`ProfitLoss`	$-3.06M	USD	1 Quarter
Net Income	`ProfitLoss`	$111.76M	USD	Annual
Net Income	`ProfitLoss`	$144.87M	USD	Annual
Net Income	`ProfitLoss`	$-3.89M	USD	1 Quarter
Net Income	`ProfitLoss`	$80.67M	USD	1 Quarter
Net Income	`ProfitLoss`	$68.35M	USD	1 Quarter
Depreciation and amortization	`DepreciationAndAmortization`	$200.47M	USD	Annual
Depreciation and amortization	`DepreciationAndAmortization`	$236.82M	USD	Annual
Depreciation and amortization	`DepreciationAndAmortization`	$223.42M	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$56.47M	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$68.64M	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$66.28M	USD	Annual
Accounts receivable, net of allowances	`IncreaseDecreaseInAccountsReceivable`	$61.64M	USD	Annual
Accounts receivable, net of allowances	`IncreaseDecreaseInAccountsReceivable`	$22.56M	USD	Annual
Accounts receivable, net of allowances	`IncreaseDecreaseInAccountsReceivable`	$-12.33M	USD	Annual
Accrued utility revenue	`IncreaseDecreaseInOtherReceivables`	$1.70M	USD	Annual
Accrued utility revenue	`IncreaseDecreaseInOtherReceivables`	$5.90M	USD	Annual
Accrued utility revenue	`IncreaseDecreaseInOtherReceivables`	$700.00K	USD	Annual
Deferred purchased gas costs	`IncreaseDecreaseInDeferredGasCost`	$52.88M	USD	Annual
Deferred purchased gas costs	`IncreaseDecreaseInDeferredGasCost`	$-22.82M	USD	Annual
Deferred purchased gas costs	`IncreaseDecreaseInDeferredGasCost`	$111.14M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$-26.00M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$15.83M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$27.67M	USD	Annual
Accrued taxes	`IncreaseDecreaseInPropertyAndOtherTaxesPayable`	$14.98M	USD	Annual
Accrued taxes	`IncreaseDecreaseInPropertyAndOtherTaxesPayable`	$925.00K	USD	Annual
Accrued taxes	`IncreaseDecreaseInPropertyAndOtherTaxesPayable`	$113.00K	USD	Annual
Other current assets and liabilities	`IncreaseDecreaseInOtherOperatingCapitalNet`	$-5.08M	USD	Annual
Other current assets and liabilities	`IncreaseDecreaseInOtherOperatingCapitalNet`	$18.95M	USD	Annual
Other current assets and liabilities	`IncreaseDecreaseInOtherOperatingCapitalNet`	$3.35M	USD	Annual
Gains on sale	`GainLossOnSaleOfPropertyPlantEquipment`	$8.04M	USD	Annual
Gains on sale	`GainLossOnSaleOfPropertyPlantEquipment`	$3.31M	USD	Annual
Gains on sale	`GainLossOnSaleOfPropertyPlantEquipment`	$4.11M	USD	Annual
Changes in undistributed stock compensation	`ShareBasedCompensation`	$6.96M	USD	Annual
Changes in undistributed stock compensation	`ShareBasedCompensation`	$6.12M	USD	Annual
Changes in undistributed stock compensation	`ShareBasedCompensation`	$5.14M	USD	Annual
AFUDC and property-related changes	`IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction`	$1.94M	USD	Annual
AFUDC and property-related changes	`IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction`	$2.27M	USD	Annual
AFUDC and property-related changes	`IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction`	$1.15M	USD	Annual
Changes in other assets and deferred charges	`IncreaseDecreaseInOtherOperatingAssets`	$21.72M	USD	Annual
Changes in other assets and deferred charges	`IncreaseDecreaseInOtherOperatingAssets`	$-11.03M	USD	Annual
Changes in other assets and deferred charges	`IncreaseDecreaseInOtherOperatingAssets`	$15.37M	USD	Annual
Changes in other liabilities and deferred credits	`IncreaseDecreaseInOtherOperatingLiabilities`	$17.75M	USD	Annual
Changes in other liabilities and deferred credits	`IncreaseDecreaseInOtherOperatingLiabilities`	$-4.43M	USD	Annual
Changes in other liabilities and deferred credits	`IncreaseDecreaseInOtherOperatingLiabilities`	$-36.38M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$252.04M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$386.32M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$346.21M	USD	Annual
Construction expenditures and property additions	`PaymentsToAcquirePropertyPlantAndEquipment`	$380.99M	USD	Annual
Construction expenditures and property additions	`PaymentsToAcquirePropertyPlantAndEquipment`	$364.28M	USD	Annual
Construction expenditures and property additions	`PaymentsToAcquirePropertyPlantAndEquipment`	$395.71M	USD	Annual
Restricted cash	`IncreaseDecreaseInRestrictedCash`	$-25.00M	USD	Annual
Restricted cash	`IncreaseDecreaseInRestrictedCash`	$-12.79M	USD	Annual
Changes in customer advances	`ChangeInCustomerAdvances`	$-7.77M	USD	Annual
Changes in customer advances	`ChangeInCustomerAdvances`	$7.77M	USD	Annual
Changes in customer advances	`ChangeInCustomerAdvances`	$-3.02M	USD	Annual
Miscellaneous inflows	`ProceedsFromOtherInvestingActivities`	$13.96M	USD	Annual
Miscellaneous inflows	`ProceedsFromOtherInvestingActivities`	$8.46M	USD	Annual
Miscellaneous inflows	`ProceedsFromOtherInvestingActivities`	$7.69M	USD	Annual
Miscellaneous outflows	`PaymentsForOtherInvestingActivities`	$2.00M	USD	Annual
Miscellaneous outflows	`PaymentsForOtherInvestingActivities`	$2.72M	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-348.04M	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-358.80M	USD	Annual
Net cash used in investing activities	`NetCashProvidedByUsedInInvestingActivities`	$-373.99M	USD	Annual
Issuance of common stock, net	`ProceedsFromIssuanceOfCommonStock`	$7.40M	USD	Annual
Issuance of common stock, net	`ProceedsFromIssuanceOfCommonStock`	$1.64M	USD	Annual
Issuance of common stock, net	`ProceedsFromIssuanceOfCommonStock`	$1.58M	USD	Annual
Dividends paid	`PaymentsOfDividendsCommonStock`	$53.04M	USD	Annual
Dividends paid	`PaymentsOfDividendsCommonStock`	$59.53M	USD	Annual
Dividends paid	`PaymentsOfDividendsCommonStock`	$47.93M	USD	Annual
Interest rate swap settlement	`PaymentsForHedgeFinancingActivities`	$21.75M	USD	Annual
Issuance of long-term debt, net	`ProceedsFromIssuanceOfLongTermDebt`	$274.60M	USD	Annual
Issuance of long-term debt, net	`ProceedsFromIssuanceOfLongTermDebt`	$489.52M	USD	Annual
Issuance of long-term debt, net	`ProceedsFromIssuanceOfLongTermDebt`	$311.29M	USD	Annual
Retirement of long-term debt	`RepaymentsOfLongTermDebt`	$330.47M	USD	Annual
Retirement of long-term debt	`RepaymentsOfLongTermDebt`	$427.04M	USD	Annual
Retirement of long-term debt	`RepaymentsOfLongTermDebt`	$137.01M	USD	Annual
Change in credit facility and commercial paper	`ProceedsFromRepaymentsOfLinesOfCredit`	$-101.00M	USD	Annual
Change in credit facility and commercial paper	`ProceedsFromRepaymentsOfLinesOfCredit`	$109.00M	USD	Annual
Change in credit facility and commercial paper	`ProceedsFromRepaymentsOfLinesOfCredit`	$2.00M	USD	Annual
Other	`ProceedsFromPaymentsForOtherFinancingActivities`	$2.00M	USD	Annual
Net cash provided by (used in) financing activities	`NetCashProvidedByUsedInFinancingActivities`	$12.60M	USD	Annual
Net cash provided by (used in) financing activities	`NetCashProvidedByUsedInFinancingActivities`	$17.38M	USD	Annual
Net cash provided by (used in) financing activities	`NetCashProvidedByUsedInFinancingActivities`	$-8.74M	USD	Annual
Change in cash and cash equivalents	`CashAndCashEquivalentsPeriodIncreaseDecrease`	$-94.16M	USD	Annual
Change in cash and cash equivalents	`CashAndCashEquivalentsPeriodIncreaseDecrease`	$3.59M	USD	Annual
Change in cash and cash equivalents	`CashAndCashEquivalentsPeriodIncreaseDecrease`	$15.55M	USD	Annual
Cash and cash equivalents at beginning of period	`CashAndCashEquivalentsAtCarryingValue`	$25.53M	USD	Point-in-time
Cash and cash equivalents at beginning of period	`CashAndCashEquivalentsAtCarryingValue`	$41.08M	USD	Point-in-time
Cash and cash equivalents at beginning of period	`CashAndCashEquivalentsAtCarryingValue`	$21.94M	USD	Point-in-time
Cash and cash equivalents at beginning of period	`CashAndCashEquivalentsAtCarryingValue`	$116.10M	USD	Point-in-time
Cash and cash equivalents at end of period	`CashAndCashEquivalentsAtCarryingValue`	$25.53M	USD	Point-in-time
Cash and cash equivalents at end of period	`CashAndCashEquivalentsAtCarryingValue`	$41.08M	USD	Point-in-time
Cash and cash equivalents at end of period	`CashAndCashEquivalentsAtCarryingValue`	$21.94M	USD	Point-in-time
Cash and cash equivalents at end of period	`CashAndCashEquivalentsAtCarryingValue`	$116.10M	USD	Point-in-time
Interest paid, net of amounts capitalized	`InterestPaidNet`	$58.73M	USD	Annual
Interest paid, net of amounts capitalized	`InterestPaidNet`	$69.84M	USD	Annual
Interest paid, net of amounts capitalized	`InterestPaidNet`	$87.44M	USD	Annual
Income taxes paid (received)	`IncomeTaxesPaidNet`	$-13.63M	USD	Annual
Income taxes paid (received)	`IncomeTaxesPaidNet`	$2.84M	USD	Annual
Income taxes paid (received)	`IncomeTaxesPaidNet`	$6.85M	USD	Annual

Stockholders Equity 49 line items

Line Item	Tag	Value	Unit	Period
Dividends declared Common, per share	`CommonStockDividendsPerShareDeclared`	$1.18	USD	Annual
Dividends declared Common, per share	`CommonStockDividendsPerShareDeclared`	$1.32	USD	Annual
Dividends declared Common, per share	`CommonStockDividendsPerShareDeclared`	$1.06	USD	Annual
Shares registered and available for issuance	`DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance`	2.10M	shares	Point-in-time
Common shares registered for issuance upon exercise of options	`ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber`	369,000.00	shares	Point-in-time
Common shares registered for issuance upon exercise of options	`ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber`	125,000.00	shares	Point-in-time
Common shares registered for issuance upon exercise of options	`ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber`	177,000.00	shares	Point-in-time
Common shares registered for issuance upon exercise of options	`ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber`	52,000.00	shares	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.31B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.23B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.41B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.17B	USD	Point-in-time
Balance, Shares	`CommonStockSharesOutstanding`	46.15M	shares	Point-in-time
Balance, Shares	`CommonStockSharesOutstanding`	46.36M	shares	Point-in-time
Common stock issuances, Value	`StockIssuedDuringPeriodValueNewIssues`	$7.33M	USD	Annual
Common stock issuances, Value	`StockIssuedDuringPeriodValueNewIssues`	$14.11M	USD	Annual
Common stock issuances, Value	`StockIssuedDuringPeriodValueNewIssues`	$11.95M	USD	Annual
Net income (loss)	`ProfitLoss`	$55.14M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$-4.41M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$62.11M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$4.01M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$57.19M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$78.83M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$132.64M	USD	Annual
Net income (loss)	`ProfitLoss`	$80.67M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$10.07M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$-3.06M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$111.76M	USD	Annual
Net income (loss)	`ProfitLoss`	$144.87M	USD	Annual
Net income (loss)	`ProfitLoss`	$-3.89M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$68.35M	USD	1 Quarter
Net income (loss)	`ProfitLoss`	$-15.75M	USD	1 Quarter
Net actuarial gain (loss) arising during the period, less amortization of unamortized benefit plan cost, net of tax (Notes 5 and 9)	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$4.99M	USD	Annual
Net actuarial gain (loss) arising during the period, less amortization of unamortized benefit plan cost, net of tax (Notes 5 and 9)	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$8.14M	USD	Annual
Net actuarial gain (loss) arising during the period, less amortization of unamortized benefit plan cost, net of tax (Notes 5 and 9)	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$-6.97M	USD	Annual
FSIRS realized and unrealized gain, net of tax (Notes 5 and 12)	`OtherComprehensiveIncomeRealizedAndUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax`	$-11.13M	USD	Annual
FSIRS realized and unrealized gain, net of tax (Notes 5 and 12)	`OtherComprehensiveIncomeRealizedAndUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax`	$1.83M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-1.74M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-2.07M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-725.00K	USD	Annual
Dividends declared Common	`DividendsCommonStock`	$55.09M	USD	Annual
Dividends declared Common	`DividendsCommonStock`	$49.29M	USD	Annual
Dividends declared Common	`DividendsCommonStock`	$61.98M	USD	Annual
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.41B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.17B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.31B	USD	Point-in-time
Balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$1.23B	USD	Point-in-time
Balance, Shares	`CommonStockSharesOutstanding`	46.15M	shares	Point-in-time
Balance, Shares	`CommonStockSharesOutstanding`	46.36M	shares	Point-in-time

Comprehensive Income 51 line items

Line Item	Tag	Value	Unit	Period
Net Income	`ProfitLoss`	$-15.75M	USD	1 Quarter
Net Income	`ProfitLoss`	$-4.41M	USD	1 Quarter
Net Income	`ProfitLoss`	$62.11M	USD	1 Quarter
Net Income	`ProfitLoss`	$57.19M	USD	1 Quarter
Net Income	`ProfitLoss`	$78.83M	USD	1 Quarter
Net Income	`ProfitLoss`	$55.14M	USD	1 Quarter
Net Income	`ProfitLoss`	$132.64M	USD	Annual
Net Income	`ProfitLoss`	$4.01M	USD	1 Quarter
Net Income	`ProfitLoss`	$10.07M	USD	1 Quarter
Net Income	`ProfitLoss`	$-3.06M	USD	1 Quarter
Net Income	`ProfitLoss`	$111.76M	USD	Annual
Net Income	`ProfitLoss`	$144.87M	USD	Annual
Net Income	`ProfitLoss`	$-3.89M	USD	1 Quarter
Net Income	`ProfitLoss`	$68.35M	USD	1 Quarter
Net Income	`ProfitLoss`	$80.67M	USD	1 Quarter
Net actuarial gain (loss)	`OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax`	$-46.41M	USD	Annual
Net actuarial gain (loss)	`OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax`	$-84.00M	USD	Annual
Net actuarial gain (loss)	`OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax`	$62.21M	USD	Annual
Amortization of prior service cost	`OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax`	$220.00K	USD	Annual
Amortization of transition obligation	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationNetOfTax`	$-538.00K	USD	Annual
Amortization of transition obligation	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationNetOfTax`	$-537.00K	USD	Annual
Amortization of net actuarial (gain)/loss, Net-of-Tax Amount	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax`	$-21.19M	USD	Annual
Amortization of net actuarial (gain)/loss, Net-of-Tax Amount	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax`	$-9.65M	USD	Annual
Amortization of net actuarial (gain)/loss, Net-of-Tax Amount	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax`	$-15.87M	USD	Annual
Prior service cost	`OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax`	$1.50M	USD	Annual
Regulatory adjustment	`OtherComprehensiveIncomeDefinedBenefitPlansRegulatoryAdjustment`	$76.65M	USD	Annual
Regulatory adjustment	`OtherComprehensiveIncomeDefinedBenefitPlansRegulatoryAdjustment`	$-26.52M	USD	Annual
Regulatory adjustment	`OtherComprehensiveIncomeDefinedBenefitPlansRegulatoryAdjustment`	$-65.68M	USD	Annual
Net defined benefit pension plans	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$4.99M	USD	Annual
Net defined benefit pension plans	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$8.14M	USD	Annual
Net defined benefit pension plans	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$-6.97M	USD	Annual
Unrealized/realized gain (loss) (Notes 5 and 12)	`OtherComprehensiveIncomeRealizedAndUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax`	$1.83M	USD	Annual
Unrealized/realized gain (loss) (Notes 5 and 12)	`OtherComprehensiveIncomeRealizedAndUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax`	$-11.13M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-1.74M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-2.07M	USD	Annual
Amounts reclassified into net income (Notes 5 and 12)	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax`	$-725.00K	USD	Annual
Net forward-starting interest rate swaps	`OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax`	$-10.41M	USD	Annual
Net forward-starting interest rate swaps	`OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax`	$3.57M	USD	Annual
Net forward-starting interest rate swaps	`OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax`	$2.07M	USD	Annual
Total other comprehensive income (loss), net of tax	`OtherComprehensiveIncomeLossNetOfTax`	$-1.41M	USD	Annual
Total other comprehensive income (loss), net of tax	`OtherComprehensiveIncomeLossNetOfTax`	$9.05M	USD	Annual
Total other comprehensive income (loss), net of tax	`OtherComprehensiveIncomeLossNetOfTax`	$-18.55M	USD	Annual
Comprehensive income	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$153.92M	USD	Annual
Comprehensive income	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$93.22M	USD	Annual
Comprehensive income	`ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest`	$131.22M	USD	Annual
Comprehensive income (loss) attributable to noncontrolling interest	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	$-524.00K	USD	Annual
Comprehensive income (loss) attributable to noncontrolling interest	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	$-692.00K	USD	Annual
Comprehensive income (loss) attributable to noncontrolling interest	`ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest`	$-447.00K	USD	Annual
Comprehensive income attributable to Southwest Gas Corporation	`ComprehensiveIncomeNetOfTax`	$154.37M	USD	Annual
Comprehensive income attributable to Southwest Gas Corporation	`ComprehensiveIncomeNetOfTax`	$131.92M	USD	Annual
Comprehensive income attributable to Southwest Gas Corporation	`ComprehensiveIncomeNetOfTax`	$93.74M	USD	Annual

Data is extracted from SEC EDGAR XBRL filings. Values shown are as reported in the filing.