$LNT
ALLIANT ENERGY CORP Stock $lnt

$lnt Overview Financials Valuation SEC Filings Company Website

2019 Q4 Form 10-K Financial Statement

#000035254120000021 Filed on February 21, 2020

Income Statement

Concept	2019 Q4	2019 Q3	2019 Q2
Revenue	$880.1M	$990.2M	$790.2M
YoY Change	0.76%	6.63%	-3.17%
Cost Of Revenue	$70.60M	$127.0M	$112.4M
YoY Change	-14.22%	-1.63%	-6.1%
Gross Profit	$809.5M	$863.2M	$677.8M
YoY Change	2.31%	7.97%	-2.67%
Gross Profit Margin	91.98%	87.17%	85.78%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$143.6M	$143.8M	$142.9M
YoY Change	10.04%	11.47%	12.52%
% of Gross Profit	17.74%	16.66%	21.08%
Operating Expenses	$648.6M	$690.9M	$620.0M
YoY Change	-3.17%	4.49%	-2.73%
Operating Profit	$160.9M	$290.0M	$149.8M
YoY Change	32.54%	13.24%	-0.93%
Interest Expense	-$24.20M	$68.00M	$69.20M
YoY Change	-8.33%	7.42%	12.89%
% of Operating Profit	-15.04%	23.45%	46.19%
Other Income/Expense, Net	-$3.400M	-$38.00M	-$41.50M
YoY Change	112.5%	4.68%	19.6%
Pretax Income	$133.3M	$252.0M	$108.3M
YoY Change	42.72%	14.65%	-7.04%
Income Tax	$19.30M	$23.00M	$11.20M
% Of Pretax Income	14.48%	9.13%	10.34%
Net Earnings	$114.0M	$229.0M	$97.10M
YoY Change	29.84%	10.04%	-5.64%
Net Earnings / Revenue	12.95%	23.13%	12.29%
Basic Earnings Per Share		$0.95
Diluted Earnings Per Share	$0.46	$0.94	$0.40
COMMON SHARES
Basic Shares Outstanding		239.1M shares	237.5M shares
Diluted Shares Outstanding		239.9M shares	238.1M shares

Balance Sheet

Concept	2019 Q4	2019 Q3	2019 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$16.00M	$194.0M	$170.0M
YoY Change	-23.81%	-19.17%	3300.0%
Cash & Equivalents	$16.00M	$193.7M	$170.2M
Short-Term Investments
Other Short-Term Assets	$144.0M	$137.1M	$151.1M
YoY Change	80.0%	8.38%	32.66%
Inventory	$227.0M	$224.0M	$206.0M
Prepaid Expenses
Receivables	$402.0M	$451.5M	$421.5M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$876.0M	$1.113B	$1.027B
YoY Change	11.58%	-1.05%	27.47%
LONG-TERM ASSETS
Property, Plant & Equipment	$13.53B	$13.13B	$12.85B
YoY Change	8.54%	9.38%	9.9%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$458.0M	$453.0M	$443.0M
YoY Change	8.79%	6.84%	5.23%
Other Assets	$1.830B	$72.60M	$68.80M
YoY Change	1940.13%	-29.72%	-20.37%
Total Long-Term Assets	$1.830B	$1.836B	$1.797B
YoY Change	4.76%	7.02%	6.15%
TOTAL ASSETS
Total Short-Term Assets	$876.0M	$1.113B	$1.027B
Total Long-Term Assets	$1.830B	$1.836B	$1.797B
Total Assets	$16.70B	$16.53B	$16.12B
YoY Change	8.27%	8.28%	10.31%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$422.0M	$497.7M	$422.5M
YoY Change	-22.33%	-0.08%	-1.99%
Accrued Expenses	$2.000M	$2.000M	$2.000M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$337.0M	$350.0M	$391.0M
YoY Change	-23.58%	155.47%	371.08%
Long-Term Debt Due	$657.0M	$656.8M	$706.8M
YoY Change	156.14%	29.78%	98.48%
Total Short-Term Liabilities	$2.054B	$2.082B	$1.949B
YoY Change	24.93%	34.48%	55.0%
LONG-TERM LIABILITIES
Long-Term Debt	$5.533B	$5.535B	$5.438B
YoY Change	5.46%	5.47%	6.06%
Other Long-Term Liabilities	$299.0M	$305.6M	$413.6M
YoY Change	4.11%	6.56%	33.25%
Total Long-Term Liabilities	$5.832B	$5.841B	$5.852B
YoY Change	5.39%	5.52%	7.61%
TOTAL LIABILITIES
Total Short-Term Liabilities	$2.054B	$2.082B	$1.949B
Total Long-Term Liabilities	$5.832B	$5.841B	$5.852B
Total Liabilities	$7.886B	$7.923B	$7.801B
YoY Change	9.87%	11.85%	16.51%
SHAREHOLDERS EQUITY
Retained Earnings	$2.766B	$2.739B	$2.598B
YoY Change	8.65%	7.86%	7.68%
Common Stock	$2.448B	$2.239B	$2.111B
YoY Change	19.54%	9.74%	8.27%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$5.205B	$4.969B	$4.700B
YoY Change
Total Liabilities & Shareholders Equity	$16.70B	$16.53B	$16.12B
YoY Change	8.27%	8.28%	10.31%

Cashflow Statement

Concept	2019 Q4	2019 Q3	2019 Q2
OPERATING ACTIVITIES
Net Income	$114.0M	$229.0M	$97.10M
YoY Change	29.84%	10.04%	-5.64%
Depreciation, Depletion And Amortization	$143.6M	$143.8M	$142.9M
YoY Change	10.04%	11.47%	12.52%
Cash From Operating Activities	$151.2M	$232.3M	$95.80M
YoY Change	76.84%	38.44%	-18.88%
INVESTING ACTIVITIES
Capital Expenditures	-$534.5M	-$351.4M	-$278.5M
YoY Change	9.51%	-7.67%	-23.57%
Acquisitions
YoY Change
Other Investing Activities	$108.3M	$97.30M	$36.30M
YoY Change	-54.3%	17.51%	-2892.31%
Cash From Investing Activities	-$426.2M	-$254.1M	-$242.2M
YoY Change	69.73%	-14.67%	-33.77%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$125.0M	$6.000M
YoY Change		37.06%	-93.6%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	93.00M	47.30M	302.8M
YoY Change	-264.02%	-87.07%	30.86%
NET CHANGE
Cash From Operating Activities	151.2M	232.3M	95.80M
Cash From Investing Activities	-426.2M	-254.1M	-242.2M
Cash From Financing Activities	93.00M	47.30M	302.8M
Net Change In Cash	-182.0M	25.50M	156.4M
YoY Change	-18.13%	-89.19%	-1065.43%
FREE CASH FLOW
Cash From Operating Activities	$151.2M	$232.3M	$95.80M
Capital Expenditures	-$534.5M	-$351.4M	-$278.5M
Free Cash Flow	$685.7M	$583.7M	$374.3M
YoY Change	19.54%	6.44%	-22.42%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2019	dei	Amendment Flag AmendmentFlag	false
CY2019	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2019	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2019	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
CY2019	dei	Entity Central Index Key EntityCentralIndexKey	0000352541
CY2018Q4	lnt	Common Stock Held In Trust Shares CommonStockHeldInTrustShares	384580	shares
CY2019Q4	lnt	Common Stock Held In Trust Shares CommonStockHeldInTrustShares	381232	shares
CY2018Q4	lnt	Common Stock Held In Trust Weighted Average Value Per Share CommonStockHeldInTrustWeightedAverageValuePerShare	25.60
CY2019Q4	lnt	Common Stock Held In Trust Weighted Average Value Per Share CommonStockHeldInTrustWeightedAverageValuePerShare	26.24
CY2018Q4	lnt	Defined Benefit Pension And Other Postretirement Benefits Plans Total Plan Assets Percentage On Common Stock DefinedBenefitPensionAndOtherPostretirementBenefitsPlansTotalPlanAssetsPercentageOnCommonStock	0.01
CY2017	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.26
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.34
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.42
CY2018Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2018Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	480000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	480000000	shares
CY2019	dei	Document Type DocumentType	10-K
CY2019	dei	Document Annual Report DocumentAnnualReport	true
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Document Transition Report DocumentTransitionReport	false
CY2019	dei	Entity Registrant Name EntityRegistrantName	ALLIANT ENERGY CORP
CY2019	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	WI
CY2019	dei	Entity Address Address Line1 EntityAddressAddressLine1	4902 N. Biltmore Lane
CY2019	dei	Entity Address City Or Town EntityAddressCityOrTown	Madison
CY2019	dei	Entity Address State Or Province EntityAddressStateOrProvince	WI
CY2019	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	53718
CY2019	dei	City Area Code CityAreaCode	608
CY2019	dei	Local Phone Number LocalPhoneNumber	458-3311
CY2019	dei	Entity File Number EntityFileNumber	1-9894
CY2019	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	39-1380265
CY2019	dei	Security12b Title Security12bTitle	Common Stock, $0.01 Par Value
CY2019	dei	Trading Symbol TradingSymbol	LNT
CY2019	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2019	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2019	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2019	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2019	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2019	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2019	dei	Entity Small Business EntitySmallBusiness	false
CY2019	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2019	dei	Entity Shell Company EntityShellCompany	false
CY2019Q2	dei	Entity Public Float EntityPublicFloat	11600000000	USD
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	245031019	shares
CY2019	us-gaap	Regulated Operating Revenue Electric Non Nuclear RegulatedOperatingRevenueElectricNonNuclear	3063600000	USD
CY2018	us-gaap	Regulated Operating Revenue Electric Non Nuclear RegulatedOperatingRevenueElectricNonNuclear	3000300000	USD
CY2017	us-gaap	Regulated Operating Revenue Electric Non Nuclear RegulatedOperatingRevenueElectricNonNuclear	2894700000	USD
CY2019	us-gaap	Regulated Operating Revenue Gas RegulatedOperatingRevenueGas	455200000	USD
CY2018	us-gaap	Regulated Operating Revenue Gas RegulatedOperatingRevenueGas	446600000	USD
CY2017	us-gaap	Regulated Operating Revenue Gas RegulatedOperatingRevenueGas	400900000	USD
CY2019	us-gaap	Regulated Operating Revenue Other RegulatedOperatingRevenueOther	46500000	USD
CY2018	us-gaap	Regulated Operating Revenue Other RegulatedOperatingRevenueOther	48000000.0	USD
CY2017	us-gaap	Regulated Operating Revenue Other RegulatedOperatingRevenueOther	47500000	USD
CY2019	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	82400000	USD
CY2018	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	39600000	USD
CY2017	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	39100000	USD
CY2019	us-gaap	Revenues Revenues	3647700000	USD
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CY2017	us-gaap	Revenues Revenues	3382200000	USD
CY2019	us-gaap	Utilities Operating Expense Fuel Used UtilitiesOperatingExpenseFuelUsed	776700000	USD
CY2018	us-gaap	Utilities Operating Expense Fuel Used UtilitiesOperatingExpenseFuelUsed	855000000.0	USD
CY2017	us-gaap	Utilities Operating Expense Fuel Used UtilitiesOperatingExpenseFuelUsed	818100000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	481400000	USD
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CY2019	us-gaap	Utilities Operating Expense Gas And Petroleum Purchased UtilitiesOperatingExpenseGasAndPetroleumPurchased	221700000	USD
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CY2019	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	712200000	USD
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CY2017	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	633200000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	567200000	USD
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CY2019	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	110800000	USD
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CY2019	us-gaap	Interest Expense InterestExpense	272900000	USD
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CY2019	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	92700000	USD
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CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-14400000	USD
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CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-17300000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-141600000	USD
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CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	636100000	USD
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CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	422300000	USD
CY2018Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	543300000	USD
CY2019Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	212000000.0	USD
CY2018Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	142700000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	425200000	USD
CY2018Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	260400000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	2054100000	USD
CY2018Q4	us-gaap	Liabilities Current LiabilitiesCurrent	1644100000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5533000000.0	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5246300000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	1714000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	1603100000	USD
CY2019Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	1211600000	USD
CY2018Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	1350500000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	484000000.0	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	509100000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	298900000	USD
CY2018Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	287200000	USD
CY2019Q4	us-gaap	Deferred Credits And Other Liabilities DeferredCreditsAndOtherLiabilities	3708500000	USD
CY2018Q4	us-gaap	Deferred Credits And Other Liabilities DeferredCreditsAndOtherLiabilities	3749900000	USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2018Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	2500000	USD
CY2018Q4	us-gaap	Common Stock Value CommonStockValue	2400000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	2445900000	USD
CY2018Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	2045500000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	2765400000	USD
CY2018Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	2545900000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	1300000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	1700000	USD
CY2019Q4	us-gaap	Common Stock Held In Trust CommonStockHeldInTrust	10000000.0	USD
CY2018Q4	us-gaap	Common Stock Held In Trust CommonStockHeldInTrust	9800000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	5205100000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	4585700000	USD
CY2019Q4	us-gaap	Minority Interest Amount Represented By Preferred Stock MinorityInterestAmountRepresentedByPreferredStock	200000000.0	USD
CY2018Q4	us-gaap	Minority Interest Amount Represented By Preferred Stock MinorityInterestAmountRepresentedByPreferredStock	200000000.0	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5405100000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4785700000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	16700700000	USD
CY2018Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	15426000000.0	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	567400000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	522300000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	467500000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	567200000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	506900000	USD
CY2017	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	461800000	USD
CY2019	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	55600000	USD
CY2018	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	67000000.0	USD
CY2017	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	139600000	USD
CY2019	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	65500000	USD
CY2018	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	51400000	USD
CY2017	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	33600000	USD
CY2019	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-19900000	USD
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-7700000	USD
CY2017	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-21700000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	471700000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	475400000	USD
CY2017	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	441200000	USD
CY2019	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	16200000	USD
CY2018	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	16200000	USD
CY2017	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	130800000	USD
CY2019	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	-40300000	USD
CY2018	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	1300000	USD
CY2017	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	-83800000	USD
CY2019	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-53800000	USD
CY2018	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-55900000	USD
CY2017	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-81700000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	9800000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	90400000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-38700000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	660400000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	527700000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	521600000	USD
CY2019	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	1538400000	USD
CY2018	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	1568300000	USD
CY2017	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	1281800000	USD
CY2019	us-gaap	Payments To Acquire Other Productive Assets PaymentsToAcquireOtherProductiveAssets	101700000	USD
CY2018	us-gaap	Payments To Acquire Other Productive Assets PaymentsToAcquireOtherProductiveAssets	65600000	USD
CY2017	us-gaap	Payments To Acquire Other Productive Assets PaymentsToAcquireOtherProductiveAssets	185100000	USD
CY2019	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	413200000	USD
CY2018	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	605300000	USD
CY2017	us-gaap	Proceeds From Collection Of Retained Interest In Securitized Receivables ProceedsFromCollectionOfRetainedInterestInSecuritizedReceivables	461800000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	60400000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	38200000	USD
CY2017	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	28300000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1287300000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1066800000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1033400000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	337700000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	312200000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	288300000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	390300000	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	196600000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	149600000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	950000000.0	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1500000000.0	USD
CY2017	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	550000000.0	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	256500000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	855700000	USD
CY2017	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	4600000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-103800000	USD
CY2018	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	26000000.0	USD
CY2017	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	171100000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-23200000	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-24000000.0	USD
CY2017	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-45200000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	619100000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	530700000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	532600000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-7800000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-8400000	USD
CY2017	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	20800000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	25500000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	33900000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	13100000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	17700000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	25500000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	33900000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	267900000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	247500000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	212600000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-20500000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	5000000.0	USD
CY2017	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	11300000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	195800000	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	299500000	USD
CY2017	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	196500000	USD
CY2019	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	187700000	USD
CY2018	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	119400000	USD
CY2017	us-gaap	Consideration Received For Beneficial Interest Obtained For Transferring Financial Asset ConsiderationReceivedForBeneficialInterestObtainedForTransferringFinancialAsset	222100000	USD
CY2016Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4062000000.0	USD
CY2017	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	457300000	USD
CY2017	us-gaap	Dividends Common Stock DividendsCommonStock	288300000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	149600000	USD
CY2017	us-gaap	Stockholders Equity Other StockholdersEquityOther	-1700000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-100000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4382200000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	512100000	USD
CY2018	us-gaap	Dividends Common Stock DividendsCommonStock	312200000	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	196600000	USD
CY2018	us-gaap	Stockholders Equity Other StockholdersEquityOther	-4800000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	2200000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4785700000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	557200000	USD
CY2019	us-gaap	Dividends Common Stock DividendsCommonStock	337700000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	390300000	USD
CY2019	us-gaap	Stockholders Equity Other StockholdersEquityOther	-10000000.0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-400000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	5405100000	USD
CY2019	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.
CY2019	us-gaap	Use Of Estimates UseOfEstimates	The preparation of the financial statements requires management to make estimates and assumptions that affect: (a) the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements; and (b) the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
CY2019	lnt	Electric Capacity Of Wind Project ElectricCapacityOfWindProject	1000	MW
CY2019Q4	us-gaap	Regulatory Assets RegulatoryAssets	1844700000	USD
CY2018Q4	us-gaap	Regulatory Assets RegulatoryAssets	1737300000	USD
CY2019Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	1423600000	USD
CY2018Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	1493200000	USD
CY2019	lnt	Electric Capacity Of Wind Project ElectricCapacityOfWindProject	1000	MW
CY2019Q4	lnt	Public Utilities Property Plant And Equipment Electric PublicUtilitiesPropertyPlantAndEquipmentElectric	13864600000	USD
CY2018Q4	lnt	Public Utilities Property Plant And Equipment Electric PublicUtilitiesPropertyPlantAndEquipmentElectric	12663600000	USD
CY2019Q4	lnt	Public Utilities Property Plant And Equipment Gas PublicUtilitiesPropertyPlantAndEquipmentGas	1462700000	USD
CY2018Q4	lnt	Public Utilities Property Plant And Equipment Gas PublicUtilitiesPropertyPlantAndEquipmentGas	1387600000	USD
CY2019Q4	lnt	Public Utilities Property Plant And Equipment General PublicUtilitiesPropertyPlantAndEquipmentGeneral	519700000	USD
CY2018Q4	lnt	Public Utilities Property Plant And Equipment General PublicUtilitiesPropertyPlantAndEquipmentGeneral	513200000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Accumulated Depreciation PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation	4601400000	USD
CY2018Q4	us-gaap	Public Utilities Property Plant And Equipment Accumulated Depreciation PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation	4314600000	USD
CY2019Q4	lnt	Net Utility Plant NetUtilityPlant	11245600000	USD
CY2018Q4	lnt	Net Utility Plant NetUtilityPlant	10249800000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Construction Work In Progress PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress	1835000000.0	USD
CY2018Q4	us-gaap	Public Utilities Property Plant And Equipment Construction Work In Progress PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress	1774800000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Other Property Plant And Equipment PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment	6100000	USD
CY2018Q4	us-gaap	Public Utilities Property Plant And Equipment Other Property Plant And Equipment PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment	6100000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Net PublicUtilitiesPropertyPlantAndEquipmentNet	13086700000	USD
CY2018Q4	us-gaap	Public Utilities Property Plant And Equipment Net PublicUtilitiesPropertyPlantAndEquipmentNet	12030700000	USD
CY2019Q4	lnt	Property Plant And Equipment Nonregulated Business Line1 PropertyPlantAndEquipmentNonregulatedBusinessLine1	82900000	USD
CY2018Q4	lnt	Property Plant And Equipment Nonregulated Business Line1 PropertyPlantAndEquipmentNonregulatedBusinessLine1	86900000	USD
CY2019Q4	lnt	Property Plant And Equipment Nonregulated Business Line2 PropertyPlantAndEquipmentNonregulatedBusinessLine2	357500000	USD
CY2018Q4	lnt	Property Plant And Equipment Nonregulated Business Line2 PropertyPlantAndEquipmentNonregulatedBusinessLine2	344800000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	440400000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	431700000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	13527100000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	12462400000	USD
CY2019Q4	lnt	Accumulated Depreciation On Property Plant And Equipment Non Regulated Business Line1 AccumulatedDepreciationOnPropertyPlantAndEquipmentNonRegulatedBusinessLine1	58500000	USD
CY2018Q4	lnt	Accumulated Depreciation On Property Plant And Equipment Non Regulated Business Line1 AccumulatedDepreciationOnPropertyPlantAndEquipmentNonRegulatedBusinessLine1	54500000	USD
CY2019Q4	lnt	Accumulated Depreciation On Property Plant And Equipment Non Regulated Business Line2 AccumulatedDepreciationOnPropertyPlantAndEquipmentNonRegulatedBusinessLine2	172400000	USD
CY2018Q4	lnt	Accumulated Depreciation On Property Plant And Equipment Non Regulated Business Line2 AccumulatedDepreciationOnPropertyPlantAndEquipmentNonRegulatedBusinessLine2	167500000	USD
CY2019	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	92700000	USD
CY2018	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	75600000	USD
CY2017	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	49700000	USD
CY2019Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet	21000000	USD
CY2019Q1	us-gaap	Business Combination Contingent Consideration Asset BusinessCombinationContingentConsiderationAsset	8000000	USD
CY2019Q4	us-gaap	Jointly Owned Utility Plant Gross Ownership Amount Of Plant In Service JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService	1864100000	USD
CY2019Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Plant Accumulated Depreciation JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation	670700000	USD
CY2019Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Construction Work In Progress JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress	673700000	USD
CY2019Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	91600000	USD
CY2018Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	91000000.0	USD
CY2019Q4	us-gaap	Costs In Excess Of Billings On Uncompleted Contracts Or Programs Expected To Be Collected Within One Year CostsInExcessOfBillingsOnUncompletedContractsOrProgramsExpectedToBeCollectedWithinOneYear	82100000	USD
CY2018Q4	us-gaap	Costs In Excess Of Billings On Uncompleted Contracts Or Programs Expected To Be Collected Within One Year CostsInExcessOfBillingsOnUncompletedContractsOrProgramsExpectedToBeCollectedWithinOneYear	74200000	USD
CY2019Q4	lnt	Fair Value Of Deferred Proceeds Of Receivables Sold FairValueOfDeferredProceedsOfReceivablesSold	187700000	USD
CY2018Q4	lnt	Fair Value Of Deferred Proceeds Of Receivables Sold FairValueOfDeferredProceedsOfReceivablesSold	119400000	USD
CY2019Q4	us-gaap	Other Receivables OtherReceivables	48000000.0	USD
CY2018Q4	us-gaap	Other Receivables OtherReceivables	76300000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	7300000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	10500000	USD
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	402100000	USD
CY2018Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	350400000	USD
CY2019Q4	us-gaap	Trade Receivables Held For Sale Amount TradeReceivablesHeldForSaleAmount	90000000	USD
CY2017	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	5185	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	236063279	shares
CY2017Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	231348646	shares
CY2016Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	227673654	shares
CY2019	lnt	Shares Of Stock Issued Shareowner Direct Plan SharesOfStockIssuedShareownerDirectPlan	501808	shares
CY2018	lnt	Shares Of Stock Issued Shareowner Direct Plan SharesOfStockIssuedShareownerDirectPlan	576965	shares
CY2017	lnt	Shares Of Stock Issued Shareowner Direct Plan SharesOfStockIssuedShareownerDirectPlan	640723	shares
CY2019	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	101478	shares
CY2018	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	5078	shares
CY2019	lnt	Other Common Stock Activity OtherCommonStockActivity	2738	shares
CY2018	lnt	Other Common Stock Activity OtherCommonStockActivity	38423	shares
CY2017	lnt	Other Common Stock Activity OtherCommonStockActivity	45847	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	245022800	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	236063279	shares
CY2017Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	231348646	shares
CY2019Q4	lnt	Shares Available For Issuance Pursuant To Various Plans SharesAvailableForIssuancePursuantToVariousPlans	12100000	shares
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-400000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	2200000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-100000	USD
CY2019Q4	us-gaap	Line Of Credit Facility Current Borrowing Capacity LineOfCreditFacilityCurrentBorrowingCapacity	1000000000	USD
CY2019Q4	us-gaap	Commercial Paper CommercialPaper	337400000	USD
CY2018Q4	us-gaap	Commercial Paper CommercialPaper	441200000	USD
CY2019Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.019
CY2018Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.028
CY2019Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	662600000	USD
CY2018Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	558800000	USD
CY2019	us-gaap	Shortterm Debt Maximum Amount Outstanding During Period ShorttermDebtMaximumAmountOutstandingDuringPeriod	600600000	USD
CY2018	us-gaap	Shortterm Debt Maximum Amount Outstanding During Period ShorttermDebtMaximumAmountOutstandingDuringPeriod	446500000	USD
CY2019	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	453500000	USD
CY2018	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	221400000	USD
CY2019	us-gaap	Short Term Debt Weighted Average Interest Rate Over Time ShortTermDebtWeightedAverageInterestRateOverTime	0.025
CY2018	us-gaap	Short Term Debt Weighted Average Interest Rate Over Time ShortTermDebtWeightedAverageInterestRateOverTime	0.022
CY2019Q4	lnt	Debt To Capital Ratios Actual Status DebtToCapitalRatiosActualStatus	0.55
CY2019Q4	lnt	Hybrid Securities Maximum Limit HybridSecuritiesMaximumLimit	0.15
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	6240300000	USD
CY2018Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	5546700000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	657200000	USD
CY2018Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	256500000	USD
CY2019Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	36900000	USD
CY2018Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	32100000	USD
CY2019Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	13200000	USD
CY2018Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	11800000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5533000000.0	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	5246300000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	657000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	8000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	333000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	408000000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	509000000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	16000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	2000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	14000000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	16000000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y
CY2019Q4	us-gaap	Lessee Operating Lease Discount Rate LesseeOperatingLeaseDiscountRate	0.04
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	10000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	20000000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	4000000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	16000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	5000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	5000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	3000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	3000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	2000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	12000000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	30000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3647700000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3534500000	USD
CY2017	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3382200000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-6600000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-1000000.0	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-41000000.0	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	24200000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-5100000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	8500000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	69700000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	67900000	USD
CY2017	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	159500000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	41400000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	29800000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	12300000	USD
CY2019	lnt	Production Tax Credits Net Of State Tax Impacts ProductionTaxCreditsNetOfStateTaxImpacts	54700000	USD
CY2018	lnt	Production Tax Credits Net Of State Tax Impacts ProductionTaxCreditsNetOfStateTaxImpacts	29500000	USD
CY2017	lnt	Production Tax Credits Net Of State Tax Impacts ProductionTaxCreditsNetOfStateTaxImpacts	31100000	USD
CY2019	us-gaap	Investment Tax Credit InvestmentTaxCredit	800000	USD
CY2018	us-gaap	Investment Tax Credit InvestmentTaxCredit	1200000	USD
CY2017	us-gaap	Investment Tax Credit InvestmentTaxCredit	1100000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	68700000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47700000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	66700000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.068
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.070
CY2017	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.055
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.086
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.052
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.061
CY2019	lnt	Effective Income Tax Rate Reconciliation Effect Of Rate Making On Property Related Differences EffectiveIncomeTaxRateReconciliationEffectOfRateMakingOnPropertyRelatedDifferences	-0.061
CY2018	lnt	Effective Income Tax Rate Reconciliation Effect Of Rate Making On Property Related Differences EffectiveIncomeTaxRateReconciliationEffectOfRateMakingOnPropertyRelatedDifferences	-0.076
CY2017	lnt	Effective Income Tax Rate Reconciliation Effect Of Rate Making On Property Related Differences EffectiveIncomeTaxRateReconciliationEffectOfRateMakingOnPropertyRelatedDifferences	-0.085
CY2019	lnt	Effective Income Tax Rate Reconciliation Amortization Of Excess Deferred Taxes EffectiveIncomeTaxRateReconciliationAmortizationOfExcessDeferredTaxes	-0.010
CY2018	lnt	Effective Income Tax Rate Reconciliation Amortization Of Excess Deferred Taxes EffectiveIncomeTaxRateReconciliationAmortizationOfExcessDeferredTaxes	-0.003
CY2017	lnt	Effective Income Tax Rate Reconciliation Amortization Of Excess Deferred Taxes EffectiveIncomeTaxRateReconciliationAmortizationOfExcessDeferredTaxes	-0.001
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.023
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.015
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0.010
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0.034
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.012
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.009
CY2017	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.008
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.108
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.084
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.125
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2021500000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1975500000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	85100000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	80500000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	2217400000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	2158400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	355400000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	299100000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	60500000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	158600000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	36600000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	47000000.0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	60500000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	59800000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	513000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	564500000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9600000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9200000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	503400000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	555300000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	1714000000.0	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	1603100000	USD
CY2019	lnt	Statute Of Limitations Expiration Period From Extended Due Date Of Federal Tax Return StatuteOfLimitationsExpirationPeriodFromExtendedDueDateOfFederalTaxReturn	P3Y
CY2019	lnt	Statuteof Limitations Expiration Periodfrom Extended Due Dateof Iowa Tax Return StatuteofLimitationsExpirationPeriodfromExtendedDueDateofIowaTaxReturn	P3Y
CY2019	lnt	Statuteof Limitations Expiration Periodfrom Extended Due Dateof Wisconsin Tax Return StatuteofLimitationsExpirationPeriodfromExtendedDueDateofWisconsinTaxReturn	P4Y
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2017	lnt	Tax Cuts And Jobs Act Of2017 Change In Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInIncomeTaxExpenseBenefit	-18100000	USD
CY2018	lnt	Tax Cuts And Jobs Act Of2017 Change In Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInIncomeTaxExpenseBenefit	-5600000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	104100000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	92200000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	94100000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	94600000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	95000000.0	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	466800000	USD
CY2019Q4	lnt	Defined Benefit Pension And Other Postretirement Benefits Plans Total Plan Assets Percentage On Common Stock DefinedBenefitPensionAndOtherPostretirementBenefitsPlansTotalPlanAssetsPercentageOnCommonStock	0.01
CY2019Q4	lnt	Common Stock Percentage In Assets Held Saving Plans CommonStockPercentageInAssetsHeldSavingPlans	0.115
CY2018Q4	lnt	Common Stock Percentage In Assets Held Saving Plans CommonStockPercentageInAssetsHeldSavingPlans	0.115
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	25500000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	25100000	USD
CY2017	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	24800000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	26000000.0	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17000000.0	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	15100000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	7300000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4900000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	6200000	USD
CY2019Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	5400000	USD
CY2019Q4	us-gaap	Share Price SharePrice	54.72
CY2019	lnt	Deferred Compensation Plan Base Salary And Incentive Compensation Percentage DeferredCompensationPlanBaseSalaryAndIncentiveCompensationPercentage	1
CY2019	lnt	Carrying Value Of Deferred Compensation CarryingValueOfDeferredCompensation	10000000.0	USD
CY2018	lnt	Carrying Value Of Deferred Compensation CarryingValueOfDeferredCompensation	9800000	USD
CY2019	lnt	Fair Market Value Of Deferred Compensation FairMarketValueOfDeferredCompensation	20900000	USD
CY2018	lnt	Fair Market Value Of Deferred Compensation FairMarketValueOfDeferredCompensation	16200000	USD
CY2019	lnt	Carrying Value Of Entity Deferred Compensation Obligations Interest And Equity Accounts CarryingValueOfEntityDeferredCompensationObligationsInterestAndEquityAccounts	21200000	USD
CY2018	lnt	Carrying Value Of Entity Deferred Compensation Obligations Interest And Equity Accounts CarryingValueOfEntityDeferredCompensationObligationsInterestAndEquityAccounts	21000000.0	USD
CY2018Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	177500000	USD
CY2017Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	184500000	USD
CY2019	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-5500000	USD
CY2018	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-10100000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	8800000	USD
CY2018	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	10400000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	26200000	USD
CY2018	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	7300000	USD
CY2019	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	6900000	USD
CY2018	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	6200000	USD
CY2019Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	196300000	USD
CY2018Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	177500000	USD
CY2019Q4	lnt	Fair Value Of Deferred Proceeds Of Receivables Sold FairValueOfDeferredProceedsOfReceivablesSold	187700000	USD
CY2018Q4	lnt	Fair Value Of Deferred Proceeds Of Receivables Sold FairValueOfDeferredProceedsOfReceivablesSold	119400000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	6919900000	USD
CY2018Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	5860800000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	499000000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Second Year PurchaseObligationDueInSecondYear	223000000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Third Year PurchaseObligationDueInThirdYear	160000000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Fourth Year PurchaseObligationDueInFourthYear	128000000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Fifth Year PurchaseObligationDueInFifthYear	84000000	USD
CY2019Q4	us-gaap	Purchase Obligation Due After Fifth Year PurchaseObligationDueAfterFifthYear	199000000	USD
CY2019Q4	us-gaap	Purchase Obligation PurchaseObligation	1293000000	USD
CY2019Q4	lnt	Individual Commitments Incurred IndividualCommitmentsIncurred	1000000	USD
CY2019Q4	lnt	Present Value Abandonment Obligation PresentValueAbandonmentObligation	39000000	USD
CY2019	us-gaap	Revenues Revenues	3647700000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	567200000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	777700000	USD
CY2019	us-gaap	Interest Expense InterestExpense	272900000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	53000000.0	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	68700000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	557200000	USD
CY2019Q4	us-gaap	Assets Assets	16700700000	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	458300000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1640100000	USD
CY2018	us-gaap	Revenues Revenues	3534500000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	506900000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	694400000	USD
CY2018	us-gaap	Interest Expense InterestExpense	247000000.0	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	54600000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	47700000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	512100000	USD
CY2018Q4	us-gaap	Assets Assets	15426000000.0	USD
CY2018Q4	us-gaap	Equity Method Investments EquityMethodInvestments	421300000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1633900000	USD
CY2017	us-gaap	Revenues Revenues	3382200000	USD
CY2017	us-gaap	Depreciation And Amortization DepreciationAndAmortization	461800000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	671200000	USD
CY2017	us-gaap	Interest Expense InterestExpense	215600000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	44800000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	66700000	USD
CY2017	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	457300000	USD
CY2017Q4	us-gaap	Assets Assets	14187800000	USD
CY2017Q4	us-gaap	Equity Method Investments EquityMethodInvestments	381400000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1466900000	USD
CY2019Q1	us-gaap	Revenues Revenues	987200000	USD
CY2019Q2	us-gaap	Revenues Revenues	790200000	USD
CY2019Q3	us-gaap	Revenues Revenues	990200000	USD
CY2019Q4	us-gaap	Revenues Revenues	880100000	USD
CY2018Q1	us-gaap	Revenues Revenues	916300000	USD
CY2018Q2	us-gaap	Revenues Revenues	816100000	USD
CY2018Q3	us-gaap	Revenues Revenues	928600000	USD
CY2018Q4	us-gaap	Revenues Revenues	873500000	USD
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	176800000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	149800000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	290200000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	160900000	USD
CY2018Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	165700000	USD
CY2018Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	151200000	USD
CY2018Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	256100000	USD
CY2018Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	121400000	USD
CY2019Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	125100000	USD
CY2019Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	94600000	USD
CY2019Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	226000000.0	USD
CY2019Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	111500000	USD
CY2018Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	120900000	USD
CY2018Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	100400000	USD
CY2018Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	205500000	USD
CY2018Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	85300000	USD
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.53
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.40
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.94
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.52
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.43
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.87
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.36

Files In Submission

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$LNT
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2019 Q4 Form 10-K Financial Statement

#000035254120000021 Filed on February 21, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$LNT ALLIANT ENERGY CORP Stock $lnt

2019 Q4 Form 10-K Financial Statement

#000035254120000021 Filed on February 21, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$LNT
ALLIANT ENERGY CORP Stock $lnt