$ALE
ALLETE INC Stock $ale

$ale Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-K Financial Statement

#000006675622000014 Filed on February 16, 2022

Income Statement

Concept	2021 Q4	2021 Q3	2021
Revenue	$399.0M	$345.4M	$1.419B
YoY Change	24.53%	17.52%	21.39%
Cost Of Revenue	$21.00M	$15.20M	$68.80M
YoY Change	16.02%	-1.3%	3.15%
Gross Profit	$378.0M	$330.2M	$1.350B
YoY Change	25.04%	18.56%	22.5%
Gross Profit Margin	94.74%	95.6%	95.15%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$60.70M	$57.50M	$231.7M
YoY Change	4.12%	7.68%	6.38%
% of Gross Profit	16.06%	17.41%	17.16%
Operating Expenses	$328.0M	$299.1M	$1.199B
YoY Change	23.35%	26.26%	26.02%
Operating Profit	$50.00M	$31.10M	$151.3M
YoY Change	37.36%	-25.24%	0.27%
Interest Expense	-$11.00M	$17.30M	$69.10M
YoY Change	-0.9%	6.13%	5.34%
% of Operating Profit	-22.0%	55.63%	45.67%
Other Income/Expense, Net	$1.900M	-$11.90M	-$40.40M
YoY Change	-57.78%	43.37%	40.28%
Pretax Income	$41.00M	$19.20M	$110.9M
YoY Change	38.05%	-42.34%	-9.17%
Income Tax	-$7.600M	-$4.900M	-$26.90M
% Of Pretax Income	-18.54%	-25.52%	-24.26%
Net Earnings	$61.90M	$27.60M	$169.2M
YoY Change	31.42%	-32.19%	-2.87%
Net Earnings / Revenue	15.51%	7.99%	11.92%
Basic Earnings Per Share	$1.18	$0.53	$3.23
Diluted Earnings Per Share	$1.18	$0.53	$3.23
COMMON SHARES
Basic Shares Outstanding		52.40M shares	52.40M shares
Diluted Shares Outstanding		52.50M shares	52.50M shares

Balance Sheet

Concept	2021 Q4	2021 Q3	2021
SHORT-TERM ASSETS
Cash & Short-Term Investments	$45.10M	$59.00M	$45.10M
YoY Change	1.81%	-25.32%	1.81%
Cash & Equivalents	$45.10M	$59.00M	$45.10M
Short-Term Investments
Other Short-Term Assets	$24.80M	$19.90M	$24.80M
YoY Change	1.22%	3.11%	1.22%
Inventory	$97.70M	$89.60M	$97.70M
Prepaid Expenses
Receivables	$123.7M	$110.2M	$123.7M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$291.3M	$278.7M	$291.3M
YoY Change	14.28%	5.13%	14.28%
LONG-TERM ASSETS
Property, Plant & Equipment	$5.100B	$5.053B	$5.136B
YoY Change	5.36%	7.57%	5.22%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$318.0M	$317.8M	$318.0M
YoY Change	5.58%	8.91%	5.58%
Other Assets	$212.9M	$179.7M	$666.4M
YoY Change	2.95%	-8.41%	7.21%
Total Long-Term Assets	$6.144B	$6.054B	$6.144B
YoY Change	5.39%	7.84%	5.39%
TOTAL ASSETS
Total Short-Term Assets	$291.3M	$278.7M	$291.3M
Total Long-Term Assets	$6.144B	$6.054B	$6.144B
Total Assets	$6.435B	$6.332B	$6.435B
YoY Change	5.76%	7.72%	5.76%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$111.0M	$101.9M	$111.0M
YoY Change	0.91%	28.99%	0.91%
Accrued Expenses	$24.90M	$20.30M	$24.90M
YoY Change	-3.11%	-8.14%	-3.11%
Deferred Revenue	$27.20M	$27.50M
YoY Change	267.57%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$214.2M	$377.4M	$214.2M
YoY Change	5.15%	-6.7%	5.15%
Total Short-Term Liabilities	$543.4M	$646.0M	$543.4M
YoY Change	18.23%	2.54%	18.23%
LONG-TERM LIABILITIES
Long-Term Debt	$1.763B	$1.649B	$1.763B
YoY Change	10.67%	2.57%	10.67%
Other Long-Term Liabilities	$280.8M	$278.1M	$996.4M
YoY Change	-1.58%	-2.59%	-3.81%
Total Long-Term Liabilities	$2.044B	$1.928B	$2.760B
YoY Change	8.81%	1.8%	4.96%
TOTAL LIABILITIES
Total Short-Term Liabilities	$543.4M	$646.0M	$543.4M
Total Long-Term Liabilities	$2.044B	$1.928B	$2.760B
Total Liabilities	$3.489B	$3.478B	$4.022B
YoY Change	6.22%	1.31%	6.12%
SHAREHOLDERS EQUITY
Retained Earnings	$900.2M	$873.4M
YoY Change	4.09%	2.77%
Common Stock	$1.537B	$1.497B
YoY Change	5.19%	2.91%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$2.413B	$2.340B	$2.413B
YoY Change
Total Liabilities & Shareholders Equity	$6.435B	$6.332B	$6.435B
YoY Change	5.76%	7.72%	5.76%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2021
OPERATING ACTIVITIES
Net Income	$61.90M	$27.60M	$169.2M
YoY Change	31.42%	-32.19%	-2.87%
Depreciation, Depletion And Amortization	$60.70M	$57.50M	$231.7M
YoY Change	4.12%	7.68%	6.38%
Cash From Operating Activities	$54.30M	$103.5M	$263.5M
YoY Change	-2.86%	4.12%	-12.11%
INVESTING ACTIVITIES
Capital Expenditures	-$89.00M	-$90.90M	$473.3M
YoY Change	-49.72%	-24.81%	-34.06%
Acquisitions			$0.00
YoY Change
Other Investing Activities	$900.0K	-$500.0K	-$2.900M
YoY Change	-134.62%	-97.99%
Cash From Investing Activities	-$88.10M	-$91.40M	-$485.2M
YoY Change	-50.95%	-37.31%	-40.31%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$69.90M
YoY Change			286.19%
Debt Paid & Issued, Net			$552.9M
YoY Change			13.16%
Cash From Financing Activities	16.10M	-14.00M	$204.2M
YoY Change	-84.49%	-114.88%	-57.96%
NET CHANGE
Cash From Operating Activities	54.30M	103.5M	$263.5M
Cash From Investing Activities	-88.10M	-91.40M	-$485.2M
Cash From Financing Activities	16.10M	-14.00M	$204.2M
Net Change In Cash	-17.70M	-1.900M	-$17.50M
YoY Change	-11.06%	-103.98%	-35.9%
FREE CASH FLOW
Cash From Operating Activities	$54.30M	$103.5M	$263.5M
Capital Expenditures	-$89.00M	-$90.90M	$473.3M
Free Cash Flow	$143.3M	$194.4M	-$209.8M
YoY Change	-38.47%	-11.76%	-49.81%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2021	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
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CY2020	ale	Morelikelythannotdefined Morelikelythannotdefined	0.50
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CY2021	dei	Entity File Number EntityFileNumber	1-3548
CY2021	dei	Entity Registrant Name EntityRegistrantName	ALLETE, Inc.
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	MN
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	41-0418150
CY2021	dei	Entity Address Address Line1 EntityAddressAddressLine1	30 West Superior Street
CY2021	dei	Entity Address City Or Town EntityAddressCityOrTown	Duluth
CY2021	dei	Entity Address State Or Province EntityAddressStateOrProvince	MN
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CY2021	dei	City Area Code CityAreaCode	218
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CY2021	dei	Security12b Title Security12bTitle	Common Stock, without par value
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CY2021	dei	Security Exchange Name SecurityExchangeName	NYSE
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CY2020	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-28800000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-900000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	110900000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	122100000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	178900000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-26900000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-39500000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-6600000	USD
CY2021	us-gaap	Profit Loss ProfitLoss	137800000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	161600000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	185500000	USD
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-31400000	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-12600000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-100000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	169200000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	174200000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	185600000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	52400000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	51900000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	51600000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	52500000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	51900000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	51700000	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.23
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.36
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.59
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.23
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.35
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.59
CY2021	us-gaap	Profit Loss ProfitLoss	137800000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	161600000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	185500000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-100000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	100000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	200000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-7400000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	7600000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-3500000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	7300000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-7500000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	3700000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	145100000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	154100000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	189200000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-31400000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-12600000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-100000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	176500000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	166700000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	189300000	USD
CY2021	us-gaap	Profit Loss ProfitLoss	137800000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	161600000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	185500000	USD
CY2021	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	2600000	USD
CY2020	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	1900000	USD
CY2019	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	2300000	USD
CY2021	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-2200000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	3200000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	5600000	USD
CY2021	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	800000	USD
CY2020	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	1300000	USD
CY2019	us-gaap	Gain Loss On Sale Of Other Assets GainLossOnSaleOfOtherAssets	1600000	USD
CY2021	us-gaap	Depreciation Depreciation	231600000	USD
CY2020	us-gaap	Depreciation Depreciation	217700000	USD
CY2019	us-gaap	Depreciation Depreciation	200600000	USD
CY2021	ale	Amortizationof Power Purchase Agreements AmortizationofPowerPurchaseAgreements	11400000	USD
CY2020	ale	Amortizationof Power Purchase Agreements AmortizationofPowerPurchaseAgreements	11300000	USD
CY2019	ale	Amortizationof Power Purchase Agreements AmortizationofPowerPurchaseAgreements	11600000	USD
CY2021	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	9900000	USD
CY2020	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	10400000	USD
CY2021	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	4300000	USD
CY2019	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	11700000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-26900000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-39500000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-6700000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	5900000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	6100000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	6300000	USD
CY2020	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	100000	USD
CY2019	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	1200000	USD
CY2021	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	1200000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2700000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-100000	USD
CY2021	ale	Provision Payments For Interim Rate Refund ProvisionPaymentsForInterimRateRefund	0	USD
CY2020	ale	Provision Payments For Interim Rate Refund ProvisionPaymentsForInterimRateRefund	0	USD
CY2019	ale	Provision Payments For Interim Rate Refund ProvisionPaymentsForInterimRateRefund	-40000000.0	USD
CY2021	ale	Provision Payments For Tax Reform Refund ProvisionPaymentsForTaxReformRefund	0	USD
CY2020	ale	Provision Payments For Tax Reform Refund ProvisionPaymentsForTaxReformRefund	200000	USD
CY2019	ale	Provision Payments For Tax Reform Refund ProvisionPaymentsForTaxReformRefund	10400000	USD
	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	23600000	USD
CY2021	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	13000000.0	USD
CY2020	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	18200000	USD
CY2019	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	-22600000	USD
CY2021	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	23500000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	1400000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	4100000	USD
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	500000	USD
CY2020	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-900000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-300000	USD
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	15000000.0	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	11800000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-8800000	USD
CY2021	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	28000000.0	USD
CY2020	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	11700000	USD
CY2019	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	-13700000	USD
CY2021	us-gaap	Pension Contributions PensionContributions	10300000	USD
CY2020	us-gaap	Pension Contributions PensionContributions	10700000	USD
CY2019	us-gaap	Pension Contributions PensionContributions	10400000	USD
CY2021	ale	Changes In Fuel Adjustment Clause Regulatory Asset And Liability ChangesInFuelAdjustmentClauseRegulatoryAssetAndLiability	-56400000	USD
CY2020	ale	Changes In Fuel Adjustment Clause Regulatory Asset And Liability ChangesInFuelAdjustmentClauseRegulatoryAssetAndLiability	5000000.0	USD
CY2019	ale	Changes In Fuel Adjustment Clause Regulatory Asset And Liability ChangesInFuelAdjustmentClauseRegulatoryAssetAndLiability	0	USD
CY2021	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	12000000.0	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	31000000.0	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	25200000	USD
CY2021	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-15000000.0	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-9500000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-17200000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	263500000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	299800000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	246900000	USD
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	6400000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	12800000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	12100000	USD
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	3600000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	8700000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	12200000	USD
CY2021	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	17600000	USD
CY2020	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	99100000	USD
CY2019	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	37900000	USD
CY2021	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	0	USD
CY2020	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	0	USD
CY2019	us-gaap	Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital	8300000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	473300000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	717800000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	597100000	USD
CY2021	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	0	USD
CY2020	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	0	USD
CY2019	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	268600000	USD
CY2021	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-2900000	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-15500000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-485200000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-812800000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-342700000	USD
CY2021	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	69900000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	18100000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	1900000	USD
CY2021	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	733000000.0	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	128200000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	672400000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	201900000	USD
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	552900000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	488600000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	72200000	USD
CY2021	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	90900000	USD
CY2020	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	414500000	USD
CY2019	us-gaap	Proceeds From Minority Shareholders ProceedsFromMinorityShareholders	103800000	USD
CY2021	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	0	USD
CY2020	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	0	USD
CY2019	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	3800000	USD
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	131900000	USD
CY2021	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	121400000	USD
CY2021	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-4800000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-2500000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-900000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	204200000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	485700000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	109300000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-17500000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-27300000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	13500000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	65200000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	92500000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	79000000.0	USD
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	47700000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	65200000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	92500000	USD
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	2946300000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	2800200000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	2335600000	USD
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.52
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.47
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.35
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	45100000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	44300000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	69300000	USD
CY2021Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	300000	USD
CY2020Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	800000	USD
CY2019Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	2800000	USD
CY2021Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	2300000	USD
CY2020Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	20100000	USD
CY2019Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	20400000	USD
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	47700000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	65200000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	92500000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	66800000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	62000000.0	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	63500000	USD
CY2021	ale	Recognitionof Rightofuse Assetsand Lease Liabilities RecognitionofRightofuseAssetsandLeaseLiabilities	0	USD
CY2020	ale	Recognitionof Rightofuse Assetsand Lease Liabilities RecognitionofRightofuseAssetsandLeaseLiabilities	0	USD
CY2019	ale	Recognitionof Rightofuse Assetsand Lease Liabilities RecognitionofRightofuseAssetsandLeaseLiabilities	28700000	USD
CY2021	ale	Increase Decreasein Accounts Payablefor Capital Additionsto Property Plantand Equipment IncreaseDecreaseinAccountsPayableforCapitalAdditionstoPropertyPlantandEquipment	-14000000.0	USD
CY2020	ale	Increase Decreasein Accounts Payablefor Capital Additionsto Property Plantand Equipment IncreaseDecreaseinAccountsPayableforCapitalAdditionstoPropertyPlantandEquipment	-67000000.0	USD
CY2019	ale	Increase Decreasein Accounts Payablefor Capital Additionsto Property Plantand Equipment IncreaseDecreaseinAccountsPayableforCapitalAdditionstoPropertyPlantandEquipment	33900000	USD
CY2021	ale	Non Cash Reclassification Of Redeemable Non Controlling Interest To Current Liabilities NonCashReclassificationOfRedeemableNonControllingInterestToCurrentLiabilities	30600000	USD
CY2020	ale	Non Cash Reclassification Of Redeemable Non Controlling Interest To Current Liabilities NonCashReclassificationOfRedeemableNonControllingInterestToCurrentLiabilities	0	USD
CY2019	ale	Non Cash Reclassification Of Redeemable Non Controlling Interest To Current Liabilities NonCashReclassificationOfRedeemableNonControllingInterestToCurrentLiabilities	0	USD
CY2021	ale	Costs Incurred Capitalized Asset Retirement Obligation Costs CostsIncurredCapitalizedAssetRetirementObligationCosts	16900000	USD
CY2020	ale	Costs Incurred Capitalized Asset Retirement Obligation Costs CostsIncurredCapitalizedAssetRetirementObligationCosts	4100000	USD
CY2019	ale	Costs Incurred Capitalized Asset Retirement Obligation Costs CostsIncurredCapitalizedAssetRetirementObligationCosts	20700000	USD
CY2021	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	2600000	USD
CY2020	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	1900000	USD
CY2019	us-gaap	Increase Decrease In Allowance For Equity Funds Used During Construction IncreaseDecreaseInAllowanceForEquityFundsUsedDuringConstruction	2300000	USD
CY2021Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	100800000	USD
CY2020Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	93500000	USD
CY2021Q4	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	24700000	USD
CY2020Q4	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	20900000	USD
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1800000	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	2500000	USD
CY2021Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	123700000	USD
CY2020Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	111900000	USD
CY2021Q4	us-gaap	Energy Related Inventory Coal EnergyRelatedInventoryCoal	18700000	USD
CY2020Q4	us-gaap	Energy Related Inventory Coal EnergyRelatedInventoryCoal	23100000	USD
CY2021Q4	us-gaap	Inventory Supplies Net Of Reserves InventorySuppliesNetOfReserves	56100000	USD
CY2020Q4	us-gaap	Inventory Supplies Net Of Reserves InventorySuppliesNetOfReserves	51100000	USD
CY2021Q4	us-gaap	Other Inventory OtherInventory	22900000	USD
CY2020Q4	us-gaap	Other Inventory OtherInventory	0	USD
CY2021Q4	us-gaap	Inventory Net InventoryNet	97700000	USD
CY2020Q4	us-gaap	Inventory Net InventoryNet	74200000	USD
CY2021	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	0	USD
CY2021Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	23300000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	25500000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	16400000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	22400000	USD
CY2021Q4	us-gaap	Real Estate Investments RealEstateInvestments	19400000	USD
CY2020Q4	us-gaap	Real Estate Investments RealEstateInvestments	18200000	USD
CY2021Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	2300000	USD
CY2020Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	20100000	USD
CY2021Q4	ale	Other Postretirement Benefit Plans OtherPostretirementBenefitPlans	64800000	USD
CY2020Q4	ale	Other Postretirement Benefit Plans OtherPostretirementBenefitPlans	34200000	USD
CY2021Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	87500000	USD
CY2020Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	86400000	USD
CY2021Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	213700000	USD
CY2020Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	206800000	USD
CY2021Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	27200000	USD
CY2020Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	7400000	USD
CY2021Q4	ale	Power Purchase Agreement Current Liability PowerPurchaseAgreementCurrentLiability	12600000	USD
CY2020Q4	ale	Power Purchase Agreement Current Liability PowerPurchaseAgreementCurrentLiability	12500000	USD
CY2021Q4	ale	Manufactured Gas Plant Current ManufacturedGasPlantCurrent	12800000	USD
CY2020Q4	ale	Manufactured Gas Plant Current ManufacturedGasPlantCurrent	0	USD
CY2021Q4	ale	Public Utilities Fuel Adjustment Clause PublicUtilitiesFuelAdjustmentClause	5000000.0	USD
CY2020Q4	ale	Public Utilities Fuel Adjustment Clause PublicUtilitiesFuelAdjustmentClause	3700000	USD
CY2021Q4	ale	Redeemable Non Controlling Interest RedeemableNonControllingInterest	30600000	USD
CY2020Q4	ale	Redeemable Non Controlling Interest RedeemableNonControllingInterest	0	USD
CY2021Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	40000000.0	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	37200000	USD
CY2021Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	133000000.0	USD
CY2020Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	66700000	USD
CY2021Q4	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	184500000	USD
CY2020Q4	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	166600000	USD
CY2021Q4	ale	Power Purchase Agreement Noncurrent Liability PowerPurchaseAgreementNoncurrentLiability	39500000	USD
CY2020Q4	ale	Power Purchase Agreement Noncurrent Liability PowerPurchaseAgreementNoncurrentLiability	52100000	USD
CY2021Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	45200000	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Noncurrent OtherAccruedLiabilitiesNoncurrent	50100000	USD
CY2021Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	280800000	USD
CY2020Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	285300000	USD
CY2021	us-gaap	Lessee Operating Lease Residual Value Guarantee Description LesseeOperatingLeaseResidualValueGuaranteeDescription	Our largest operating lease is for the dragline at BNI Energy which includes a termination payment at the end of the lease term if we do not exercise our purchase option.
CY2021Q4	us-gaap	Residual Value Of Leased Asset ResidualValueOfLeasedAsset	3000000	USD
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	6700000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	8300000	USD
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	6700000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	8300000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	16400000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	22400000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	16400000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	22400000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	5100000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	3300000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	3000000.0	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	2800000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2800000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	5000000.0	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	22000000.0	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	5600000	USD
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	16400000	USD
CY2021Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	4800000	USD
CY2021Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	11600000	USD
CY2021	us-gaap	Revenue Performance Obligation Description Of Payment Terms RevenuePerformanceObligationDescriptionOfPaymentTerms	Payment terms and conditions vary across our businesses. Aside from taconite-producing Large Power Customers, payment terms generally require payment to be made within 15 to 30 days from the end of the period that the service has been rendered. In the case of its taconite-producing Large Power Customers, as permitted by the MPUC, Minnesota Power requires weekly payments for electric usage based on monthly energy usage estimates.
CY2021Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	23300000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	25500000	USD
CY2021	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	2700000	USD
CY2020	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	2600000	USD
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	8700000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	14700000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	18700000	USD
CY2021	ale	Morelikelythannotdefined Morelikelythannotdefined	0.50
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	5100200000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4840800000	USD
CY2019Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	160300000	USD
CY2020	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	8300000	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	1400000	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	3600000	USD
CY2020	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	200000	USD
CY2020Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	166600000	USD
CY2021	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	8800000	USD
CY2021	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	4500000	USD
CY2021	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	5200000	USD
CY2021	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	9800000	USD
CY2021Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	184500000	USD
CY2021Q4	us-gaap	Jointly Owned Utility Plant Gross Ownership Amount Of Plant In Service JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService	783700000	USD
CY2021Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Plant Accumulated Depreciation JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation	329600000	USD
CY2021Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Construction Work In Progress JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress	30100000	USD
CY2020Q4	us-gaap	Jointly Owned Utility Plant Gross Ownership Amount Of Plant In Service JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService	764800000	USD
CY2020Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Plant Accumulated Depreciation JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation	304800000	USD
CY2020Q4	us-gaap	Jointly Owned Utility Plant Ownership Amount Of Construction Work In Progress JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress	15000000.0	USD
CY2021Q4	ale	Conservation Improvement Program Goal Next Fiscal Year ConservationImprovementProgramGoalNextFiscalYear	10700000	USD
CY2021Q4	ale	Conservation Improvement Program Goal In2 Years ConservationImprovementProgramGoalIn2Years	10900000	USD
CY2021	us-gaap	Types Of Net Regulatory Assets Earning Returns TypesOfNetRegulatoryAssetsEarningReturns	With the exception of the regulatory asset for Boswell Units 1 and 2 net plant and equipment, no other regulatory assets are currently earning a return.
CY2021Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	511800000	USD
CY2020Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	480900000	USD
CY2021Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	8600000	USD
CY2020Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	7600000	USD
CY2021Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	536100000	USD
CY2020Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	524800000	USD
CY2021Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	544700000	USD
CY2020Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	532400000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	1000000	USD
CY2021Q4	ale	Availableforsale Securities Debt Maturities After One Year Through Three Years Fair Value AvailableforsaleSecuritiesDebtMaturitiesAfterOneYearThroughThreeYearsFairValue	2300000	USD
CY2021Q4	ale	Availableforsale Securities Debt Maturities After Three Years Through Five Years Fair Value AvailableforsaleSecuritiesDebtMaturitiesAfterThreeYearsThroughFiveYearsFairValue	2100000	USD
CY2021Q4	ale	Availableforsale Securities Debt Maturities After Five Years Fair Value AvailableforsaleSecuritiesDebtMaturitiesAfterFiveYearsFairValue	800000	USD
CY2021Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	1986400000	USD
CY2020Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	1806400000	USD
CY2021Q4	us-gaap	Equity Method Investments EquityMethodInvestments	318000000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	301200000	USD
CY2021	us-gaap	Property Plant And Equipment Impairment PropertyPlantAndEquipmentImpairment	The Company assesses the impairment of property, plant, and equipment whenever events or changes in circumstances indicate that the carrying amount of property, plant, and equipment assets may not be recoverable.
CY2021Q4	us-gaap	Debt Current DebtCurrent	214200000	USD
CY2020Q4	us-gaap	Debt Current DebtCurrent	203700000	USD
CY2021Q4	us-gaap	Deferred Finance Costs Current Net DeferredFinanceCostsCurrentNet	200000	USD
CY2021Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1763200000	USD
CY2021Q4	ale	Debt Instrument Actual Indebtedness To Total Capital Ratio DebtInstrumentActualIndebtednessToTotalCapitalRatio	0.41
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1593200000	USD
CY2021Q4	us-gaap	Deferred Finance Costs Noncurrent Net DeferredFinanceCostsNoncurrentNet	8800000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	214500000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	89700000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	74400000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	386700000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	77200000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	1143900000	USD
CY2021Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	9000000.0	USD
CY2020Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	9500000	USD
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	1977400000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	1796900000	USD
CY2021Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	214200000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	203700000	USD
CY2021Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1763200000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1593200000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	169200000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	169200000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	52400000	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	100000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	52500000	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.23
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.23
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	10800000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	174200000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	174200000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	51900000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	51900000	shares
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.36
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.35
CY2019	us-gaap	Net Income Loss NetIncomeLoss	185600000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	185600000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	51600000	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	100000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	51700000	shares
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.59
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.59
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	100000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	0	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	0	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	100000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-37200000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-48800000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-27800000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	9800000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	21700000	USD
CY2021	us-gaap	Deferred Other Tax Expense Benefit DeferredOtherTaxExpenseBenefit	-500000	USD
CY2020	us-gaap	Deferred Other Tax Expense Benefit DeferredOtherTaxExpenseBenefit	-500000	USD
CY2019	us-gaap	Deferred Other Tax Expense Benefit DeferredOtherTaxExpenseBenefit	-600000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-26900000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-39500000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-6700000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-26900000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-39500000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-6600000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	110900000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	122100000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	178900000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	23300000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	25600000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	37600000	USD
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	8600000	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	7700000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	17200000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Credits Other IncomeTaxReconciliationTaxCreditsOther	53500000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Credits Other IncomeTaxReconciliationTaxCreditsOther	62700000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Credits Other IncomeTaxReconciliationTaxCreditsOther	50700000	USD
CY2021	ale	Effective Income Tax Rate Reconciliation Regulatory Differences EffectiveIncomeTaxRateReconciliationRegulatoryDifferences	-9500000	USD
CY2020	ale	Effective Income Tax Rate Reconciliation Regulatory Differences EffectiveIncomeTaxRateReconciliationRegulatoryDifferences	-9900000	USD
CY2019	ale	Effective Income Tax Rate Reconciliation Regulatory Differences EffectiveIncomeTaxRateReconciliationRegulatoryDifferences	-8800000	USD
CY2021	ale	Effective Income Taxrate Reconciliation Stock Basis Difference EffectiveIncomeTaxrateReconciliationStockBasisDifference	0	USD
CY2020	ale	Effective Income Taxrate Reconciliation Stock Basis Difference EffectiveIncomeTaxrateReconciliationStockBasisDifference	0	USD
CY2019	ale	Effective Income Taxrate Reconciliation Stock Basis Difference EffectiveIncomeTaxrateReconciliationStockBasisDifference	1700000	USD
CY2021	us-gaap	Income Tax Reconciliation Minority Interest Income Expense IncomeTaxReconciliationMinorityInterestIncomeExpense	-6300000	USD
CY2020	us-gaap	Income Tax Reconciliation Minority Interest Income Expense IncomeTaxReconciliationMinorityInterestIncomeExpense	-2700000	USD
CY2019	us-gaap	Income Tax Reconciliation Minority Interest Income Expense IncomeTaxReconciliationMinorityInterestIncomeExpense	0	USD
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	500000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	0	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost	0	USD
CY2021	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-2600000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-2900000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-3600000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-26900000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-39500000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-6600000	USD
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.243
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.324
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.037
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	44500000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	67600000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	54800000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	61400000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	67500000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	60700000	USD
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CY2021Q4	ale	Power Purchase Agreements Deferred Tax Asset PowerPurchaseAgreementsDeferredTaxAsset	16500000	USD
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CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	69000000.0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	69900000	USD
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CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	691500000	USD
CY2021Q4	ale	Deferred Tax Liabilities Regulatory Assetsfor Benefit Obligations DeferredTaxLiabilitiesRegulatoryAssetsforBenefitObligations	54900000	USD
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CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1400000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1400000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1600000	USD
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CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	100000	USD
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CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	USD
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CY2021Q1	us-gaap	Revenues Revenues	339200000	USD
CY2021Q2	us-gaap	Revenues Revenues	335600000	USD
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CY2021Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	42000000.0	USD
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CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	27600000	USD
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CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	217800000	USD
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CY2021	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	476400000	USD
CY2020	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	657200000	USD
CY2021Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.99
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.53
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.53
CY2021Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.18
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CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.53
CY2021Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.18
CY2020Q1	us-gaap	Revenues Revenues	311600000	USD
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CY2020Q4	us-gaap	Revenues Revenues	320400000	USD
CY2020Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	60200000	USD
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CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	49800000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	70500000	USD
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CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	31200000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	49700000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.37
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.66
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.60
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.96
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CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.60
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.96

Files In Submission

Name	View Source	Status
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report.css	Edgar Link	pending
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$ALE
ALLETE INC Stock $ale

2021 Q4 Form 10-K Financial Statement

#000006675622000014 Filed on February 16, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ALE ALLETE INC Stock $ale

2021 Q4 Form 10-K Financial Statement

#000006675622000014 Filed on February 16, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ALE
ALLETE INC Stock $ale