10-K Filing

MDU RESOURCES GROUP INC CIK: 67716 FY 2023

Filing Information

Form Type	10-K
Accession Number	`0000067716-24-000017`
Period End Date	20231231
Filing Date	20240222
Fiscal Year	2023
Fiscal Period	FY
XBRL Instance	mdu-20231231_htm.xml

Filing Contents

This filing contains the following financial statements:

Balance Sheet 95 Income Statement 72 Cash Flow Statement 155 Stockholders Equity 35 Comprehensive Income 33

Balance Sheet 95 line items

Line Item	Tag	Value	Unit	Period
Cash, cash equivalents and restricted cash	`CashAndCashEquivalentsAtCarryingValue`	$70.43M	USD	Point-in-time
Cash, cash equivalents and restricted cash	`CashAndCashEquivalentsAtCarryingValue`	$76.97M	USD	Point-in-time
Receivables, net	`ReceivablesNetCurrent`	$942.78M	USD	Point-in-time
Receivables, net	`ReceivablesNetCurrent`	$1.06B	USD	Point-in-time
Inventories	`InventoryNet`	$87.39M	USD	Point-in-time
Inventories	`InventoryNet`	$64.25M	USD	Point-in-time
Current regulatory assets	`RegulatoryAssetsCurrent`	$165.09M	USD	Point-in-time
Current regulatory assets	`RegulatoryAssetsCurrent`	$172.49M	USD	Point-in-time
Prepayments and other current assets	`OtherAssetsCurrent`	$55.12M	USD	Point-in-time
Prepayments and other current assets	`OtherAssetsCurrent`	$84.08M	USD	Point-in-time
Current assets of discontinued operations	`DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets`	$592.52M	USD	Point-in-time
Current assets of discontinued operations	`DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets`	-	USD	Point-in-time
Total current assets	`AssetsCurrent`	$2.01B	USD	Point-in-time
Total current assets	`AssetsCurrent`	$1.36B	USD	Point-in-time
Property, plant and equipment	`PropertyPlantAndEquipmentGross`	$7.34B	USD	Point-in-time
Property, plant and equipment	`PropertyPlantAndEquipmentGross`	$6.87B	USD	Point-in-time
Less accumulated depreciation and amortization	`AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment`	$2.10B	USD	Point-in-time
Less accumulated depreciation and amortization	`AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment`	$2.12B	USD	Point-in-time
Less accumulated depreciation and amortization	`AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment`	$2.22B	USD	Point-in-time
Net property, plant and equipment	`PropertyPlantAndEquipmentNet`	$5.12B	USD	Point-in-time
Net property, plant and equipment	`PropertyPlantAndEquipmentNet`	$4.51B	USD	Point-in-time
Net property, plant and equipment	`PropertyPlantAndEquipmentNet`	$4.78B	USD	Point-in-time
Goodwill	`Goodwill`	$488.96M	USD	Point-in-time
Goodwill	`Goodwill`	$488.96M	USD	Point-in-time
Other intangible assets, net	`IntangibleAssetsNetExcludingGoodwill`	$4.10M	USD	Point-in-time
Other intangible assets, net	`IntangibleAssetsNetExcludingGoodwill`	$2.00M	USD	Point-in-time
Regulatory assets	`RegulatoryAssetsNoncurrent`	$329.66M	USD	Point-in-time
Regulatory assets	`RegulatoryAssetsNoncurrent`	$447.10M	USD	Point-in-time
Investments	`LongTermInvestments`	$128.83M	USD	Point-in-time
Investments	`LongTermInvestments`	$124.23M	USD	Point-in-time
Operating lease right-of-use assets	`OperatingLeaseRightOfUseAsset`	$74.36M	USD	Point-in-time
Operating lease right-of-use assets	`OperatingLeaseRightOfUseAsset`	$73.50M	USD	Point-in-time
Other	`OtherAssetsNoncurrent`	$161.90M	USD	Point-in-time
Other	`OtherAssetsNoncurrent`	$211.87M	USD	Point-in-time
Noncurrent assets of discontinued operations	`DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent`	$1.69B	USD	Point-in-time
Noncurrent assets of discontinued operations	`DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent`	-	USD	Point-in-time
Total noncurrent assets	`AssetsNoncurrent`	$6.47B	USD	Point-in-time
Total noncurrent assets	`AssetsNoncurrent`	$7.65B	USD	Point-in-time
Total assets	`Assets`	$9.66B	USD	Point-in-time
Total assets	`Assets`	$7.83B	USD	Point-in-time
Total assets	`Assets`	$8.91B	USD	Point-in-time
Short-term borrowings	`ShortTermBorrowings`	$38.50M	USD	Point-in-time
Short-term borrowings	`ShortTermBorrowings`	$95.00M	USD	Point-in-time
Long-term debt due within one year	`LongTermDebtCurrent`	$47.82M	USD	Point-in-time
Long-term debt due within one year	`LongTermDebtCurrent`	$61.32M	USD	Point-in-time
Accounts payable	`AccountsPayableCurrent`	$475.21M	USD	Point-in-time
Accounts payable	`AccountsPayableCurrent`	$525.56M	USD	Point-in-time
Taxes payable	`TaxesPayableCurrent`	$62.31M	USD	Point-in-time
Taxes payable	`TaxesPayableCurrent`	$58.11M	USD	Point-in-time
Dividends payable	`DividendsPayableCurrent`	$45.24M	USD	Point-in-time
Dividends payable	`DividendsPayableCurrent`	$25.46M	USD	Point-in-time
Accrued compensation	`EmployeeRelatedLiabilitiesCurrent`	$85.51M	USD	Point-in-time
Accrued compensation	`EmployeeRelatedLiabilitiesCurrent`	$59.47M	USD	Point-in-time
Operating lease liabilities due within one year	`OperatingLeaseLiabilityCurrent`	$22.88M	USD	Point-in-time
Operating lease liabilities due within one year	`OperatingLeaseLiabilityCurrent`	$21.31M	USD	Point-in-time
Regulatory liabilities due within one year	`RegulatoryLiabilityCurrent`	$70.76M	USD	Point-in-time
Regulatory liabilities due within one year	`RegulatoryLiabilityCurrent`	$26.44M	USD	Point-in-time
Other accrued liabilities	`OtherLiabilitiesCurrent`	$181.47M	USD	Point-in-time
Other accrued liabilities	`OtherLiabilitiesCurrent`	$156.03M	USD	Point-in-time
Current liabilities of discontinued operations	`LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent`	-	USD	Point-in-time
Current liabilities of discontinued operations	`LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent`	$496.92M	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$1.08B	USD	Point-in-time
Total current liabilities	`LiabilitiesCurrent`	$1.48B	USD	Point-in-time
Long-term debt	`LongTermDebtNoncurrent`	$2.24B	USD	Point-in-time
Long-term debt	`LongTermDebtNoncurrent`	$2.32B	USD	Point-in-time
Deferred income taxes	`DeferredIncomeTaxLiabilitiesNet`	$455.50M	USD	Point-in-time
Deferred income taxes	`DeferredIncomeTaxLiabilitiesNet`	$458.55M	USD	Point-in-time
Asset retirement obligations	`AssetRetirementObligationsNoncurrent`	$384.37M	USD	Point-in-time
Asset retirement obligations	`AssetRetirementObligationsNoncurrent`	$372.87M	USD	Point-in-time
Regulatory liabilities	`RegulatoryLiabilityNoncurrent`	$448.45M	USD	Point-in-time
Regulatory liabilities	`RegulatoryLiabilityNoncurrent`	$521.05M	USD	Point-in-time
Operating lease liabilities	`OperatingLeaseLiabilityNoncurrent`	$52.87M	USD	Point-in-time
Operating lease liabilities	`OperatingLeaseLiabilityNoncurrent`	$51.65M	USD	Point-in-time
Other	`OtherLiabilitiesNoncurrent`	$199.68M	USD	Point-in-time
Other	`OtherLiabilitiesNoncurrent`	$180.60M	USD	Point-in-time
Noncurrent liabilities of discontinued operations	`LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent`	$765.90M	USD	Point-in-time
Noncurrent liabilities of discontinued operations	`LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent`	-	USD	Point-in-time
Total noncurrent liabilities	`LiabilitiesNoncurrent`	$3.85B	USD	Point-in-time
Total noncurrent liabilities	`LiabilitiesNoncurrent`	$4.59B	USD	Point-in-time
Commitments and contingencies	`CommitmentsAndContingencies`	-	USD	Point-in-time
Commitments and contingencies	`CommitmentsAndContingencies`	-	USD	Point-in-time
Common stock Authorized - 500,000,000 shares, $1.00 par value Shares issued - 203,689,090 at December 31, 2023 and 204,162,814 at December 31, 2022	`CommonStockValueOutstanding`	$203.69M	USD	Point-in-time
Common stock Authorized - 500,000,000 shares, $1.00 par value Shares issued - 203,689,090 at December 31, 2023 and 204,162,814 at December 31, 2022	`CommonStockValueOutstanding`	$204.16M	USD	Point-in-time
Other paid-in capital	`AdditionalPaidInCapitalCommonStock`	$1.47B	USD	Point-in-time
Other paid-in capital	`AdditionalPaidInCapitalCommonStock`	$1.47B	USD	Point-in-time
Retained earnings	`RetainedEarningsAccumulatedDeficit`	$1.95B	USD	Point-in-time
Retained earnings	`RetainedEarningsAccumulatedDeficit`	$1.25B	USD	Point-in-time
Accumulated other comprehensive loss	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-18.38M	USD	Point-in-time
Accumulated other comprehensive loss	`AccumulatedOtherComprehensiveIncomeLossNetOfTax`	$-30.58M	USD	Point-in-time
Treasury stock at cost - 538,921 shares at December 31, 2022	`TreasuryStockCommonValue`	$3.63M	USD	Point-in-time
Treasury stock at cost - 538,921 shares at December 31, 2022	`TreasuryStockCommonValue`	-	USD	Point-in-time
Total stockholders' equity	`StockholdersEquity`	$3.59B	USD	Point-in-time
Total stockholders' equity	`StockholdersEquity`	$2.91B	USD	Point-in-time
Total liabilities and stockholders' equity	`LiabilitiesAndStockholdersEquity`	$9.66B	USD	Point-in-time
Total liabilities and stockholders' equity	`LiabilitiesAndStockholdersEquity`	$7.83B	USD	Point-in-time

Income Statement 72 line items

Line Item	Tag	Value	Unit	Period
Revenues	`Revenues`	$4.66B	USD	Annual
Revenues	`Revenues`	$4.44B	USD	Annual
Revenues	`Revenues`	$3.45B	USD	Annual
Total operation and maintenance	`SellingGeneralAndAdministrativeExpense`	$2.83B	USD	Annual
Total operation and maintenance	`SellingGeneralAndAdministrativeExpense`	$2.97B	USD	Annual
Total operation and maintenance	`SellingGeneralAndAdministrativeExpense`	$2.21B	USD	Annual
Purchased natural gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$757.88M	USD	Annual
Purchased natural gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$742.97M	USD	Annual
Purchased natural gas sold	`UtilitiesOperatingExpenseGasAndPetroleumPurchased`	$483.12M	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$213.60M	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$198.24M	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$210.03M	USD	Annual
Taxes, other than income	`TaxesExcludingIncomeAndExciseTaxes`	$157.99M	USD	Annual
Taxes, other than income	`TaxesExcludingIncomeAndExciseTaxes`	$196.05M	USD	Annual
Taxes, other than income	`TaxesExcludingIncomeAndExciseTaxes`	$186.17M	USD	Annual
Electric fuel and purchased power	`UtilitiesOperatingExpensePurchasedPower`	$74.11M	USD	Annual
Electric fuel and purchased power	`UtilitiesOperatingExpensePurchasedPower`	$92.01M	USD	Annual
Electric fuel and purchased power	`UtilitiesOperatingExpensePurchasedPower`	$107.88M	USD	Annual
Operating expenses	`OperatingExpenses`	$3.12B	USD	Annual
Operating expenses	`OperatingExpenses`	$4.07B	USD	Annual
Operating expenses	`OperatingExpenses`	$4.23B	USD	Annual
Operating income	`OperatingIncomeLoss`	$370.00M	USD	Annual
Operating income	`OperatingIncomeLoss`	$331.05M	USD	Annual
Operating income	`OperatingIncomeLoss`	$425.98M	USD	Annual
Realized gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	-	USD	Annual
Realized gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	$186.56M	USD	Annual
Realized gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	-	USD	Annual
Other income	`OtherNonoperatingIncomeExpense`	$11.23M	USD	Annual
Other income	`OtherNonoperatingIncomeExpense`	$25.72M	USD	Annual
Other income	`OtherNonoperatingIncomeExpense`	$41.67M	USD	Annual
Interest expense	`InterestExpense`	$80.70M	USD	Annual
Interest expense	`InterestExpense`	$114.31M	USD	Annual
Interest expense	`InterestExpense`	$70.71M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest`	$300.53M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest`	$286.07M	USD	Annual
Income before income taxes	`IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest`	$539.90M	USD	Annual
Income taxes	`IncomeTaxExpenseBenefit`	$59.47M	USD	Annual
Income taxes	`IncomeTaxExpenseBenefit`	$43.54M	USD	Annual
Income taxes	`IncomeTaxExpenseBenefit`	$49.76M	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$242.52M	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$250.77M	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$480.43M	USD	Annual
Discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$135.61M	USD	Annual
Discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$116.72M	USD	Annual
Discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$-65.72M	USD	Annual
Net income	`NetIncomeLoss`	$414.71M	USD	Annual
Net income	`NetIncomeLoss`	$367.49M	USD	Annual
Net income	`NetIncomeLoss`	$378.13M	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerBasicShare`	$2.36	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerBasicShare`	$1.23	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerBasicShare`	$1.20	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare`	$0.58	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare`	$0.67	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare`	$-0.32	USD	Annual
Earnings per share - basic (in usd per share)	`EarningsPerShareBasic`	$1.87	USD	Annual
Earnings per share - basic (in usd per share)	`EarningsPerShareBasic`	$1.81	USD	Annual
Earnings per share - basic (in usd per share)	`EarningsPerShareBasic`	$2.04	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerDilutedShare`	$2.36	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerDilutedShare`	$1.20	USD	Annual
Income from continuing operations (in usd per share)	`IncomeLossFromContinuingOperationsPerDilutedShare`	$1.23	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare`	$0.58	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare`	$-0.33	USD	Annual
Discontinued operations, net of tax (in usd per share)	`DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare`	$0.67	USD	Annual
Earnings per share - diluted (in usd per share)	`EarningsPerShareDiluted`	$1.81	USD	Annual
Earnings per share - diluted (in usd per share)	`EarningsPerShareDiluted`	$2.03	USD	Annual
Earnings per share - diluted (in usd per share)	`EarningsPerShareDiluted`	$1.87	USD	Annual
Weighted average common shares outstanding - basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	203.36M	shares	Annual
Weighted average common shares outstanding - basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	203.64M	shares	Annual
Weighted average common shares outstanding - basic (in shares)	`WeightedAverageNumberOfSharesOutstandingBasic`	202.08M	shares	Annual
Weighted average common shares outstanding - diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	203.94M	shares	Annual
Weighted average common shares outstanding - diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	203.46M	shares	Annual
Weighted average common shares outstanding - diluted (in shares)	`WeightedAverageNumberOfDilutedSharesOutstanding`	202.38M	shares	Annual

Cash Flow Statement 155 line items

Line Item	Tag	Value	Unit	Period
Reclassification adjustment for loss on derivative instruments included in net income, tax	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax`	$-177.00K	USD	Annual
Reclassification adjustment for loss on derivative instruments included in net income, tax	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax`	$-145.00K	USD	Annual
Reclassification adjustment for loss on derivative instruments included in net income, tax	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax`	$-15.00K	USD	Annual
Postretirement liability gains (losses) arising during the period, tax	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax`	$-3.96M	USD	Annual
Net income	`NetIncomeLoss`	$367.49M	USD	Annual
Net income	`NetIncomeLoss`	$378.13M	USD	Annual
Postretirement liability gains (losses) arising during the period, tax	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax`	$201.00K	USD	Annual
Postretirement liability gains (losses) arising during the period, tax	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax`	$-1.63M	USD	Annual
Net income	`NetIncomeLoss`	$414.71M	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax`	$615.00K	USD	Annual
Less: income (loss) from discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$-65.72M	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax`	$78.00K	USD	Annual
Less: income (loss) from discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$116.72M	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax`	$597.00K	USD	Annual
Less: income (loss) from discontinued operations, net of tax	`IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity`	$135.61M	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetTax`	-	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$480.43M	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$250.77M	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetTax`	$1.09M	USD	Annual
Income from continuing operations	`IncomeLossFromContinuingOperations`	$242.52M	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetTax`	-	USD	Annual
Net unrealized loss on available-for-sale investments arising during the period, tax	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax`	$-67.00K	USD	Annual
Net unrealized loss on available-for-sale investments arising during the period, tax	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax`	$46.00K	USD	Annual
Net unrealized loss on available-for-sale investments arising during the period, tax	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax`	$-177.00K	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax`	$-31.00K	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax`	$-36.00K	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$213.60M	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$198.24M	USD	Annual
Depreciation and amortization	`DepreciationDepletionAndAmortization`	$210.03M	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, tax	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax`	$-11.00K	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$27.39M	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$21.25M	USD	Annual
Deferred income taxes	`DeferredIncomeTaxExpenseBenefit`	$-4.41M	USD	Annual
Provision for credit losses	`ProvisionForDoubtfulAccounts`	$5.59M	USD	Annual
Provision for credit losses	`ProvisionForDoubtfulAccounts`	$1.04M	USD	Annual
Provision for credit losses	`ProvisionForDoubtfulAccounts`	$13.62M	USD	Annual
Amortization of debt issuance costs	`AmortizationOfFinancingCosts`	$978.00K	USD	Annual
Amortization of debt issuance costs	`AmortizationOfFinancingCosts`	$930.00K	USD	Annual
Amortization of debt issuance costs	`AmortizationOfFinancingCosts`	$1.21M	USD	Annual
Employee stock-based compensation costs	`ShareBasedCompensation`	$6.31M	USD	Annual
Employee stock-based compensation costs	`ShareBasedCompensation`	$12.86M	USD	Annual
Employee stock-based compensation costs	`ShareBasedCompensation`	$8.98M	USD	Annual
Pension and postretirement benefit plan net periodic benefit credit	`PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	$-7.32M	USD	Annual
Pension and postretirement benefit plan net periodic benefit credit	`PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	$-5.38M	USD	Annual
Pension and postretirement benefit plan net periodic benefit credit	`PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash`	$-5.99M	USD	Annual
Unrealized losses (gains) on investments	`UnrealizedGainLossOnInvestments`	$-10.21M	USD	Annual
Unrealized losses (gains) on investments	`UnrealizedGainLossOnInvestments`	$6.10M	USD	Annual
Unrealized losses (gains) on investments	`UnrealizedGainLossOnInvestments`	$7.49M	USD	Annual
Gains on sales of assets	`GainLossOnDispositionOfAssets1`	$6.63M	USD	Annual
Gains on sales of assets	`GainLossOnDispositionOfAssets1`	$6.42M	USD	Annual
Gains on sales of assets	`GainLossOnDispositionOfAssets1`	$8.52M	USD	Annual
Gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	-	USD	Annual
Gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	$186.56M	USD	Annual
Gain on tax-free exchange of the retained shares in Knife River	`DeconsolidationRevaluationOfRetainedInvestmentGainOrLossAmount`	-	USD	Annual
Receivables	`IncreaseDecreaseInReceivables`	$75.38M	USD	Annual
Receivables	`IncreaseDecreaseInReceivables`	$330.81M	USD	Annual
Receivables	`IncreaseDecreaseInReceivables`	$-110.43M	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$-138.00K	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$27.59M	USD	Annual
Inventories	`IncreaseDecreaseInInventories`	$15.55M	USD	Annual
Other current assets	`IncreaseDecreaseInOtherCurrentAssets`	$52.88M	USD	Annual
Other current assets	`IncreaseDecreaseInOtherCurrentAssets`	$9.40M	USD	Annual
Other current assets	`IncreaseDecreaseInOtherCurrentAssets`	$67.39M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$172.66M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$-76.68M	USD	Annual
Accounts payable	`IncreaseDecreaseInAccountsPayable`	$25.51M	USD	Annual
Other current liabilities	`IncreaseDecreaseInOtherCurrentLiabilities`	$67.00M	USD	Annual
Other current liabilities	`IncreaseDecreaseInOtherCurrentLiabilities`	$3.46M	USD	Annual
Other current liabilities	`IncreaseDecreaseInOtherCurrentLiabilities`	$7.57M	USD	Annual
Pension and postretirement benefit plan contributions	`PensionAndOtherPostretirementBenefitContributions`	$7.64M	USD	Annual
Pension and postretirement benefit plan contributions	`PensionAndOtherPostretirementBenefitContributions`	$82.00K	USD	Annual
Pension and postretirement benefit plan contributions	`PensionAndOtherPostretirementBenefitContributions`	$83.00K	USD	Annual
Other noncurrent changes	`IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet`	$22.68M	USD	Annual
Other noncurrent changes	`IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet`	$10.58M	USD	Annual
Other noncurrent changes	`IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet`	$51.79M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInOperatingActivitiesContinuingOperations`	$492.76M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInOperatingActivitiesContinuingOperations`	$298.95M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInOperatingActivitiesContinuingOperations`	$307.65M	USD	Annual
Net cash (used in) provided by discontinued operations	`CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations`	$196.83M	USD	Annual
Net cash (used in) provided by discontinued operations	`CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations`	$202.41M	USD	Annual
Net cash (used in) provided by discontinued operations	`CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations`	$-160.13M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$510.06M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$495.78M	USD	Annual
Net cash provided by operating activities	`NetCashProvidedByUsedInOperatingActivities`	$332.63M	USD	Annual
Capital expenditures	`PaymentsToAcquireProductiveAssets`	$519.73M	USD	Annual
Capital expenditures	`PaymentsToAcquireProductiveAssets`	$485.20M	USD	Annual
Capital expenditures	`PaymentsToAcquireProductiveAssets`	$478.43M	USD	Annual
Acquisitions, net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	-	USD	Annual
Acquisitions, net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	-	USD	Annual
Acquisitions, net of cash acquired	`PaymentsToAcquireBusinessesNetOfCashAcquired`	$2.50M	USD	Annual
Net proceeds from sale or disposition of property	`ProceedsFromSaleOfProductiveAssets`	$14.59M	USD	Annual
Net proceeds from sale or disposition of property	`ProceedsFromSaleOfProductiveAssets`	$16.47M	USD	Annual
Net proceeds from sale or disposition of property	`ProceedsFromSaleOfProductiveAssets`	$11.34M	USD	Annual
Cost of removal, net of salvage value	`PaymentsForProceedsFromRemovalCosts`	$11.36M	USD	Annual
Cost of removal, net of salvage value	`PaymentsForProceedsFromRemovalCosts`	$11.78M	USD	Annual
Cost of removal, net of salvage value	`PaymentsForProceedsFromRemovalCosts`	$-1.17M	USD	Annual
Investments	`PaymentsForProceedsFromInvestments`	$-16.30M	USD	Annual
Investments	`PaymentsForProceedsFromInvestments`	$4.14M	USD	Annual
Investments	`PaymentsForProceedsFromInvestments`	$3.14M	USD	Annual
Net cash used in continuing operations	`NetCashProvidedByUsedInInvestingActivitiesContinuingOperations`	$-485.78M	USD	Annual
Net cash used in continuing operations	`NetCashProvidedByUsedInInvestingActivitiesContinuingOperations`	$-483.00M	USD	Annual
Net cash used in continuing operations	`NetCashProvidedByUsedInInvestingActivitiesContinuingOperations`	$-487.61M	USD	Annual
Net cash used in discontinued operations	`CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations`	$-55.01M	USD	Annual
Net cash used in discontinued operations	`CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations`	$-155.88M	USD	Annual
Net cash used in discontinued operations	`CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations`	$-398.27M	USD	Annual
Net cash used in investing activities of continuing operations	`NetCashProvidedByUsedInInvestingActivities`	$-638.88M	USD	Annual
Net cash used in investing activities of continuing operations	`NetCashProvidedByUsedInInvestingActivities`	$-885.88M	USD	Annual
Net cash used in investing activities of continuing operations	`NetCashProvidedByUsedInInvestingActivities`	$-540.79M	USD	Annual
Issuance of short-term borrowings	`ProceedsFromShortTermDebt`	$810.00M	USD	Annual
Issuance of short-term borrowings	`ProceedsFromShortTermDebt`	$50.00M	USD	Annual
Issuance of short-term borrowings	`ProceedsFromShortTermDebt`	$38.50M	USD	Annual
Repayment of short-term borrowings	`RepaymentsOfShortTermDebt`	-	USD	Annual
Repayment of short-term borrowings	`RepaymentsOfShortTermDebt`	$100.00M	USD	Annual
Repayment of short-term borrowings	`RepaymentsOfShortTermDebt`	$460.90M	USD	Annual
Issuance of long-term debt	`ProceedsFromIssuanceOfLongTermDebt`	$726.70M	USD	Annual
Issuance of long-term debt	`ProceedsFromIssuanceOfLongTermDebt`	$272.04M	USD	Annual
Issuance of long-term debt	`ProceedsFromIssuanceOfLongTermDebt`	$373.05M	USD	Annual
Repayment of long-term debt	`RepaymentsOfLongTermDebt`	$793.00M	USD	Annual
Repayment of long-term debt	`RepaymentsOfLongTermDebt`	$65.76M	USD	Annual
Repayment of long-term debt	`RepaymentsOfLongTermDebt`	$24.76M	USD	Annual
Debt issuance costs	`PaymentsOfDebtIssuanceCosts`	$918.00K	USD	Annual
Debt issuance costs	`PaymentsOfDebtIssuanceCosts`	$2.52M	USD	Annual
Debt issuance costs	`PaymentsOfDebtIssuanceCosts`	$1.13M	USD	Annual
Proceeds from issuance of common stock	`ProceedsFromIssuanceOfCommonStock`	$-150.00K	USD	Annual
Proceeds from issuance of common stock	`ProceedsFromIssuanceOfCommonStock`	$88.77M	USD	Annual
Proceeds from issuance of common stock	`ProceedsFromIssuanceOfCommonStock`	-	USD	Annual
Dividends paid	`PaymentsOfDividends`	$171.35M	USD	Annual
Dividends paid	`PaymentsOfDividends`	$176.91M	USD	Annual
Dividends paid	`PaymentsOfDividends`	$161.32M	USD	Annual
Repurchase of common stock	`PaymentsForRepurchaseOfCommonStock`	$7.40M	USD	Annual
Repurchase of common stock	`PaymentsForRepurchaseOfCommonStock`	$6.70M	USD	Annual
Repurchase of common stock	`PaymentsForRepurchaseOfCommonStock`	$4.81M	USD	Annual
Tax withholding on stock-based compensation	`PaymentsRelatedToTaxWithholdingForShareBasedCompensation`	$4.13M	USD	Annual
Tax withholding on stock-based compensation	`PaymentsRelatedToTaxWithholdingForShareBasedCompensation`	$3.04M	USD	Annual
Tax withholding on stock-based compensation	`PaymentsRelatedToTaxWithholdingForShareBasedCompensation`	$4.90M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInFinancingActivitiesContinuingOperations`	$102.95M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInFinancingActivitiesContinuingOperations`	$111.11M	USD	Annual
Net cash provided by continuing operations	`NetCashProvidedByUsedInFinancingActivitiesContinuingOperations`	$155.28M	USD	Annual
Net cash provided by (used in) discontinued operations	`CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations`	$281.76M	USD	Annual
Net cash provided by (used in) discontinued operations	`CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations`	$-112.00K	USD	Annual
Net cash provided by (used in) discontinued operations	`CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations`	$93.51M	USD	Annual
Net cash provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$384.71M	USD	Annual
Net cash provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$155.17M	USD	Annual
Net cash provided by financing activities	`NetCashProvidedByUsedInFinancingActivities`	$204.62M	USD	Annual
Increase (decrease) in cash, cash equivalents and restricted cash	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect`	$-5.39M	USD	Annual
Increase (decrease) in cash, cash equivalents and restricted cash	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect`	$26.36M	USD	Annual
Increase (decrease) in cash, cash equivalents and restricted cash	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect`	$-3.54M	USD	Annual
Cash, cash equivalents and restricted cash - beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$59.55M	USD	Point-in-time
Cash, cash equivalents and restricted cash - beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$54.16M	USD	Point-in-time
Cash, cash equivalents and restricted cash - beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$80.52M	USD	Point-in-time
Cash, cash equivalents and restricted cash - beginning of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$76.97M	USD	Point-in-time
Cash, cash equivalents and restricted cash - end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$76.97M	USD	Point-in-time
Cash, cash equivalents and restricted cash - end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$59.55M	USD	Point-in-time
Cash, cash equivalents and restricted cash - end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$80.52M	USD	Point-in-time
Cash, cash equivalents and restricted cash - end of year	`CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations`	$54.16M	USD	Point-in-time

Stockholders Equity 35 line items

Line Item	Tag	Value	Unit	Period
Common stock, beginning balance (in shares)	`CommonStockSharesIssued`	203.69M	shares	Point-in-time
Common stock, beginning balance (in shares)	`CommonStockSharesIssued`	204.16M	shares	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.38B	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.08B	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$2.91B	USD	Point-in-time
Beginning balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.59B	USD	Point-in-time
Treasury stock, common, beginning balance (in shares)	`TreasuryStockCommonShares`	538,921.00	shares	Point-in-time
Net income	`NetIncomeLoss`	$378.13M	USD	Annual
Net income	`NetIncomeLoss`	$367.49M	USD	Annual
Net income	`NetIncomeLoss`	$414.71M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$7.07M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$10.42M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$-107.00K	USD	Annual
Dividends declared on common stock	`DividendsCommonStockCash`	$178.76M	USD	Annual
Dividends declared on common stock	`DividendsCommonStockCash`	$174.08M	USD	Annual
Dividends declared on common stock	`DividendsCommonStockCash`	$142.03M	USD	Annual
Employee stock-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions`	$6.78M	USD	Annual
Employee stock-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions`	$10.25M	USD	Annual
Employee stock-based compensation	`AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions`	$14.71M	USD	Annual
Repurchase of common stock	`TreasuryStockValueAcquiredCostMethod`	$6.70M	USD	Annual
Repurchase of common stock	`TreasuryStockValueAcquiredCostMethod`	$7.40M	USD	Annual
Repurchase of common stock	`TreasuryStockValueAcquiredCostMethod`	$4.81M	USD	Annual
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings	`AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueTreasuryStockReissuedThroughShareBasedPaymentArrangement`	$-4.90M	USD	Annual
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings	`AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueTreasuryStockReissuedThroughShareBasedPaymentArrangement`	$-4.13M	USD	Annual
Issuance of common stock upon vesting of stock-based compensation, net of shares used for tax withholdings	`AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueTreasuryStockReissuedThroughShareBasedPaymentArrangement`	$-3.04M	USD	Annual
Issuance of common stock	`StockIssuedDuringPeriodValueNewIssues`	$7.16M	USD	Annual
Issuance of common stock	`StockIssuedDuringPeriodValueNewIssues`	$1.33M	USD	Annual
Issuance of common stock	`StockIssuedDuringPeriodValueNewIssues`	$88.77M	USD	Annual
Common stock, ending balance (in shares)	`CommonStockSharesIssued`	203.69M	shares	Point-in-time
Common stock, ending balance (in shares)	`CommonStockSharesIssued`	204.16M	shares	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.38B	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.08B	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$2.91B	USD	Point-in-time
Ending balance	`StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest`	$3.59B	USD	Point-in-time
Treasury stock, common, ending balance (in shares)	`TreasuryStockCommonShares`	538,921.00	shares	Point-in-time

Comprehensive Income 33 line items

Line Item	Tag	Value	Unit	Period
Net income	`NetIncomeLoss`	$414.71M	USD	Annual
Net income	`NetIncomeLoss`	$367.49M	USD	Annual
Net income	`NetIncomeLoss`	$378.13M	USD	Annual
Reclassification adjustment for loss on derivative instruments included in net income, net of tax of $15, $177 and $145 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax`	$-81.00K	USD	Annual
Reclassification adjustment for loss on derivative instruments included in net income, net of tax of $15, $177 and $145 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax`	$-413.00K	USD	Annual
Reclassification adjustment for loss on derivative instruments included in net income, net of tax of $15, $177 and $145 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax`	$-446.00K	USD	Annual
Postretirement liability gains (losses) arising during the period, net of tax of $(201), $3,965 and $1,626 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax`	$-12.01M	USD	Annual
Postretirement liability gains (losses) arising during the period, net of tax of $(201), $3,965 and $1,626 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax`	$-4.88M	USD	Annual
Postretirement liability gains (losses) arising during the period, net of tax of $(201), $3,965 and $1,626 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax`	$646.00K	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, net of tax of $78, $597 and $615 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax`	$1.87M	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, net of tax of $78, $597 and $615 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax`	$242.00K	USD	Annual
Amortization of postretirement liability losses included in net periodic benefit credit, net of tax of $78, $597 and $615 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax`	$1.82M	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, net of tax of $0, $(1,086) and $0 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetNetOfTax`	$-3.27M	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, net of tax of $0, $(1,086) and $0 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetNetOfTax`	-	USD	Annual
Reclassification of postretirement liability adjustment from regulatory asset, net of tax of $0, $(1,086) and $0 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentToAccumulatedOtherComprehensiveIncomePostretirementLiabilityAdjustmentFromRegulatoryAssetNetOfTax`	-	USD	Annual
Postretirement liability adjustment	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$-10.56M	USD	Annual
Postretirement liability adjustment	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$-6.75M	USD	Annual
Postretirement liability adjustment	`OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax`	$404.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments arising during the period, net of tax of $46, $(177) and $(67) in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax`	$-667.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments arising during the period, net of tax of $46, $(177) and $(67) in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax`	$-252.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments arising during the period, net of tax of $46, $(177) and $(67) in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax`	$173.00K	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, net of tax of $11, $31 and $36 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax`	$-134.00K	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, net of tax of $11, $31 and $36 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax`	$-43.00K	USD	Annual
Reclassification adjustment for loss on available-for-sale investments included in net income, net of tax of $11, $31 and $36 in 2023, 2022 and 2021, respectively	`OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax`	$-114.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments	`OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax`	$-553.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments	`OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax`	$216.00K	USD	Annual
Net unrealized gain (loss) on available-for-sale investments	`OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax`	$-118.00K	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$7.07M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$10.42M	USD	Annual
Other comprehensive income (loss)	`OtherComprehensiveIncomeLossNetOfTax`	$-107.00K	USD	Annual
Comprehensive income attributable to common stockholders	`ComprehensiveIncomeNetOfTax`	$377.91M	USD	Annual
Comprehensive income attributable to common stockholders	`ComprehensiveIncomeNetOfTax`	$385.20M	USD	Annual
Comprehensive income attributable to common stockholders	`ComprehensiveIncomeNetOfTax`	$414.60M	USD	Annual

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