$AWK
American Water Works Company, Inc. Stock $awk

$awk Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000141063621000101 Filed on February 24, 2021

Income Statement

Concept	2020 Q4	2020	2019 Q4
Revenue	$923.0M	$3.777B	$902.0M
YoY Change	2.33%	4.63%	6.12%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$153.0M	$604.0M	$152.0M
YoY Change	0.66%	3.78%	7.8%
% of Gross Profit
Operating Expenses	$660.0M	$2.529B	$635.0M
YoY Change	3.94%	5.55%	5.48%
Operating Profit	$263.0M	$1.248B	$224.0M
YoY Change	17.41%	2.8%	-9.68%
Interest Expense	-$99.00M	-$395.0M	-$98.00M
YoY Change	1.02%	3.4%	7.69%
% of Operating Profit	-37.64%	-31.65%	-43.75%
Other Income/Expense, Net	$17.00M	-$324.0M	$14.00M
YoY Change	21.43%	-14.96%	-6.67%
Pretax Income	$181.0M	$924.0M	$136.0M
YoY Change	33.09%	10.92%	-20.0%
Income Tax	$36.00M	$215.0M	$38.00M
% Of Pretax Income	19.89%	23.27%	27.94%
Net Earnings	$145.0M	$709.0M	$98.00M
YoY Change	47.96%	14.17%	-12.5%
Net Earnings / Revenue	15.71%	18.77%	10.86%
Basic Earnings Per Share	$0.80	$3.91	$0.54
Diluted Earnings Per Share	$0.80	$3.91	$0.54
COMMON SHARES
Basic Shares Outstanding	181.3M shares	181.0M shares	180.8M shares
Diluted Shares Outstanding		182.0M shares

Balance Sheet

Concept	2020 Q4	2020	2019 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$547.0M	$547.0M	$60.00M
YoY Change	811.67%	811.67%	-53.85%
Cash & Equivalents	$547.0M	$547.0M	$60.00M
Short-Term Investments
Other Short-Term Assets	$127.0M	$978.0M	$118.0M
YoY Change	7.63%	11.9%	24.21%
Inventory	$47.00M	$47.00M	$44.00M
Prepaid Expenses
Receivables	$321.0M	$334.0M	$294.0M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$1.906B	$1.906B	$1.285B
YoY Change	48.33%	48.33%	64.53%
LONG-TERM ASSETS
Property, Plant & Equipment	$19.71B	$19.81B	$18.23B
YoY Change	8.11%	8.02%	4.73%
Goodwill	$1.504B		$1.540B
YoY Change	-2.34%		-2.22%
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$196.0M	$1.378B	$207.0M
YoY Change	-5.31%	-7.76%	228.57%
Total Long-Term Assets	$22.86B	$22.86B	$21.40B
YoY Change	6.84%	6.84%	4.67%
TOTAL ASSETS
Total Short-Term Assets	$1.906B	$1.906B	$1.285B
Total Long-Term Assets	$22.86B	$22.86B	$21.40B
Total Assets	$24.77B	$24.77B	$22.68B
YoY Change	9.19%	9.19%	6.87%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$189.0M	$189.0M	$203.0M
YoY Change	-6.9%	-6.9%	16.0%
Accrued Expenses	$591.0M	$679.0M	$596.0M
YoY Change	-0.84%	-0.15%	7.19%
Deferred Revenue
YoY Change
Short-Term Debt	$1.282B	$1.282B	$786.0M
YoY Change	63.1%	63.1%	-18.46%
Long-Term Debt Due	$329.0M	$329.0M	$28.00M
YoY Change	1075.0%	1075.0%	-60.56%
Total Short-Term Liabilities	$2.881B	$2.881B	$2.045B
YoY Change	40.88%	40.88%	-2.34%
LONG-TERM LIABILITIES
Long-Term Debt	$9.333B	$9.333B	$8.644B
YoY Change	7.97%	7.97%	14.1%
Other Long-Term Liabilities	$83.00M	$3.985B	$78.00M
YoY Change	6.41%	0.15%	0.0%
Total Long-Term Liabilities	$83.00M	$13.32B	$78.00M
YoY Change	6.41%	5.51%	0.0%
TOTAL LIABILITIES
Total Short-Term Liabilities	$2.881B	$2.881B	$2.045B
Total Long-Term Liabilities	$83.00M	$13.32B	$78.00M
Total Liabilities	$2.964B	$18.31B	$2.123B
YoY Change	39.61%	10.57%	-2.26%
SHAREHOLDERS EQUITY
Retained Earnings	$102.0M		-$207.0M
YoY Change	-149.28%		-55.39%
Common Stock	$6.749B		$6.702B
YoY Change	0.7%		0.65%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$348.0M		$338.0M
YoY Change	2.96%		13.8%
Treasury Stock Shares	5.168M shares		5.091M shares
Shareholders Equity	$6.454B	$6.454B	$6.121B
YoY Change
Total Liabilities & Shareholders Equity	$24.77B	$24.77B	$22.68B
YoY Change	9.19%	9.19%	6.87%

Cashflow Statement

Concept	2020 Q4	2020	2019 Q4
OPERATING ACTIVITIES
Net Income	$145.0M	$709.0M	$98.00M
YoY Change	47.96%	14.17%	-12.5%
Depreciation, Depletion And Amortization	$153.0M	$604.0M	$152.0M
YoY Change	0.66%	3.78%	7.8%
Cash From Operating Activities	$438.0M	$1.426B	$438.0M
YoY Change	0.0%	3.11%	11.17%
INVESTING ACTIVITIES
Capital Expenditures	-$508.0M	$1.822B	-$539.0M
YoY Change	-5.75%	10.16%	19.78%
Acquisitions		$135.0M
YoY Change		-42.55%
Other Investing Activities	-$107.0M	-$239.0M	-$152.0M
YoY Change	-29.61%	-17.87%	270.73%
Cash From Investing Activities	-$615.0M	-$2.061B	-$691.0M
YoY Change	-11.0%	5.96%	40.73%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$0.00
YoY Change		-100.0%
Debt Paid & Issued, Net		$342.0M
YoY Change		-30.91%
Cash From Financing Activities	154.0M	$1.120B	228.0M
YoY Change	-32.46%	126.72%	62.86%
NET CHANGE
Cash From Operating Activities	438.0M	$1.426B	438.0M
Cash From Investing Activities	-615.0M	-$2.061B	-691.0M
Cash From Financing Activities	154.0M	$1.120B	228.0M
Net Change In Cash	-23.00M	$485.0M	-25.00M
YoY Change	-8.0%	-813.24%	-158.14%
FREE CASH FLOW
Cash From Operating Activities	$438.0M	$1.426B	$438.0M
Capital Expenditures	-$508.0M	$1.822B	-$539.0M
Free Cash Flow	$946.0M	-$396.0M	$977.0M
YoY Change	-3.17%	46.13%	15.76%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0001410636
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1	P3Y
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	001-34028
CY2020	dei	Entity Registrant Name EntityRegistrantName	AMERICAN WATER WORKS COMPANY, INC.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	51-0063696
CY2020Q2	dei	Entity Public Float EntityPublicFloat	20390800000	USD
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	1 Water Street
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Camden
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	NJ
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	08102-1658
CY2020	dei	City Area Code CityAreaCode	856
CY2020	dei	Local Phone Number LocalPhoneNumber	955-4001
CY2020	dei	Security12b Title Security12bTitle	Common stock, par value $0.01 per share
CY2020	dei	Trading Symbol TradingSymbol	AWK
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2021Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	181439255	shares
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	25614000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	23941000000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	5904000000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	5709000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	19710000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	18232000000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	547000000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	60000000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	29000000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	31000000	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	60000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	41000000	USD
CY2020Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	321000000	USD
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	294000000	USD
CY2020Q4	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	206000000	USD
CY2019Q4	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	172000000	USD
CY2020Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	47000000	USD
CY2019Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	44000000	USD
CY2020Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	629000000	USD
CY2019Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	566000000	USD
CY2020Q4	us-gaap	Other Assets Current OtherAssetsCurrent	127000000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	118000000	USD
CY2020Q4	us-gaap	Assets Current AssetsCurrent	1906000000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	1285000000	USD
CY2020Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	1127000000	USD
CY2019Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	1128000000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	95000000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	103000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	1504000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	1501000000	USD
CY2020Q4	awk	Intangible Assets Noncurrent IntangibleAssetsNoncurrent	173000000	USD
CY2019Q4	awk	Intangible Assets Noncurrent IntangibleAssetsNoncurrent	159000000	USD
CY2020Q4	awk	Prepaid Post Retirement Assets Noncurrent PrepaidPostRetirementAssetsNoncurrent	55000000	USD
CY2019Q4	awk	Prepaid Post Retirement Assets Noncurrent PrepaidPostRetirementAssetsNoncurrent	67000000	USD
CY2020Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	196000000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	207000000	USD
CY2020Q4	us-gaap	Regulated Entity Other Assets Noncurrent RegulatedEntityOtherAssetsNoncurrent	3150000000	USD
CY2019Q4	us-gaap	Regulated Entity Other Assets Noncurrent RegulatedEntityOtherAssetsNoncurrent	3165000000	USD
CY2020Q4	us-gaap	Assets Assets	24766000000	USD
CY2019Q4	us-gaap	Assets Assets	22682000000	USD
CY2020Q4	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
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	186466707	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	185903727	shares
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	2000000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	2000000	USD
CY2020Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	6747000000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	6700000000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	102000000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-207000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-49000000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-36000000	USD
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	5168215	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	5090855	shares
CY2020Q4	us-gaap	Treasury Stock Value TreasuryStockValue	348000000	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	338000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	6454000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	6121000000	USD
CY2020Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	9329000000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	8639000000	USD
CY2020Q4	us-gaap	Preferred Stock Redemption Amount PreferredStockRedemptionAmount	4000000	USD
CY2019Q4	us-gaap	Preferred Stock Redemption Amount PreferredStockRedemptionAmount	5000000	USD
CY2020Q4	awk	Long Term Debt Includes Redeemable Preferred Stock At Redemption Value LongTermDebtIncludesRedeemablePreferredStockAtRedemptionValue	9333000000	USD
CY2019Q4	awk	Long Term Debt Includes Redeemable Preferred Stock At Redemption Value LongTermDebtIncludesRedeemablePreferredStockAtRedemptionValue	8644000000	USD
CY2020Q4	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	15787000000	USD
CY2019Q4	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	14765000000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	1282000000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	786000000	USD
CY2020Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	329000000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	28000000	USD
CY2020Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	189000000	USD
CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	203000000	USD
CY2020Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	591000000	USD
CY2019Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	596000000	USD
CY2020Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	50000000	USD
CY2019Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	46000000	USD
CY2020Q4	us-gaap	Interest Payable Current InterestPayableCurrent	88000000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	84000000	USD
CY2020Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	137000000	USD
CY2019Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	128000000	USD
CY2020Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	215000000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	174000000	USD
CY2020Q4	us-gaap	Liabilities Current LiabilitiesCurrent	2881000000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	2045000000	USD
CY2020Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	270000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Noncurrent ContractWithCustomerLiabilityNoncurrent	240000000	USD
CY2020Q4	awk	Deferred Income Tax Liabilities Netand Investment Tax Credits DeferredIncomeTaxLiabilitiesNetandInvestmentTaxCredits	2113000000	USD
CY2019Q4	awk	Deferred Income Tax Liabilities Netand Investment Tax Credits DeferredIncomeTaxLiabilitiesNetandInvestmentTaxCredits	1893000000	USD
CY2020Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	1770000000	USD
CY2019Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	1806000000	USD
CY2020Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	81000000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	89000000	USD
CY2020Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	388000000	USD
CY2019Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	411000000	USD
CY2020Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	83000000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	78000000	USD
CY2020Q4	us-gaap	Liabilities Other Than Longterm Debt Noncurrent LiabilitiesOtherThanLongtermDebtNoncurrent	4705000000	USD
CY2019Q4	us-gaap	Liabilities Other Than Longterm Debt Noncurrent LiabilitiesOtherThanLongtermDebtNoncurrent	4517000000	USD
CY2020Q4	us-gaap	Contributions In Aid Of Construction ContributionsInAidOfConstruction	1393000000	USD
CY2019Q4	us-gaap	Contributions In Aid Of Construction ContributionsInAidOfConstruction	1355000000	USD
CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	24766000000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	22682000000	USD
CY2020	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3777000000	USD
CY2019	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3610000000	USD
CY2018	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3440000000	USD
CY2020	us-gaap	Utilities Operating Expense Maintenance And Operations UtilitiesOperatingExpenseMaintenanceAndOperations	1622000000	USD
CY2019	us-gaap	Utilities Operating Expense Maintenance And Operations UtilitiesOperatingExpenseMaintenanceAndOperations	1544000000	USD
CY2018	us-gaap	Utilities Operating Expense Maintenance And Operations UtilitiesOperatingExpenseMaintenanceAndOperations	1479000000	USD
CY2020	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	604000000	USD
CY2019	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	582000000	USD
CY2018	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	545000000	USD
CY2020	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	303000000	USD
CY2019	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	280000000	USD
CY2018	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	277000000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-34000000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	20000000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	57000000	USD
CY2020	us-gaap	Operating Expenses OperatingExpenses	2529000000	USD
CY2019	us-gaap	Operating Expenses OperatingExpenses	2440000000	USD
CY2018	us-gaap	Operating Expenses OperatingExpenses	2338000000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	1248000000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	1170000000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	1102000000	USD
CY2020	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-395000000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-382000000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-350000000	USD
CY2020	awk	Benefit Costs Non Operating Net BenefitCostsNonOperatingNet	-49000000	USD
CY2019	awk	Benefit Costs Non Operating Net BenefitCostsNonOperatingNet	-16000000	USD
CY2018	awk	Benefit Costs Non Operating Net BenefitCostsNonOperatingNet	-20000000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	22000000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	29000000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	15000000	USD
CY2020	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-324000000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-337000000	USD
CY2018	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-315000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	924000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	833000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	787000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	215000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	212000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	222000000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	709000000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	621000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	565000000	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	0	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-2000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	709000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	621000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	567000000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.91
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.44
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.16
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.91
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.43
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.15
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	181000000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	181000000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	180000000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	182000000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	181000000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	180000000	shares
CY2020	us-gaap	Net Income Loss NetIncomeLoss	709000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	621000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	567000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-3000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-20000000	USD
CY2020	us-gaap	Increase Decrease In Pension And Postretirement Obligations IncreaseDecreaseInPensionAndPostretirementObligations	12000000	USD
CY2019	us-gaap	Increase Decrease In Pension And Postretirement Obligations IncreaseDecreaseInPensionAndPostretirementObligations	-8000000	USD
CY2018	us-gaap	Increase Decrease In Pension And Postretirement Obligations IncreaseDecreaseInPensionAndPostretirementObligations	-60000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-3000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-3000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-4000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-7000000	USD
CY2020	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Pension TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsPension	0	USD
CY2019	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Pension TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsPension	0	USD
CY2018	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Pension TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsPension	-22000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-1000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-1000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-5000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-13000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-2000000	USD
CY2020	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Hedge TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsHedge	0	USD
CY2019	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Hedge TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsHedge	0	USD
CY2018	awk	Tax Cutsand Jobs Actof2017 Reclassificationfrom Aoc Ito Retained Earnings Hedge TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsHedge	2000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-2000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	45000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	696000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	619000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	612000000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	709000000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	621000000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	565000000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	604000000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	582000000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	545000000	USD
CY2020	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	207000000	USD
CY2019	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	208000000	USD
CY2018	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	195000000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	34000000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	28000000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	33000000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	0	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-34000000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	20000000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	0	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	57000000	USD
CY2020	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	-14000000	USD
CY2019	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	17000000	USD
CY2018	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	23000000	USD
CY2020	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	20000000	USD
CY2019	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	41000000	USD
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-20000000	USD
CY2020	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	97000000	USD
CY2019	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	25000000	USD
CY2018	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	17000000	USD
CY2020	us-gaap	Pension And Other Postretirement Benefit Contributions PensionAndOtherPostretirementBenefitContributions	39000000	USD
CY2019	us-gaap	Pension And Other Postretirement Benefit Contributions PensionAndOtherPostretirementBenefitContributions	31000000	USD
CY2018	us-gaap	Pension And Other Postretirement Benefit Contributions PensionAndOtherPostretirementBenefitContributions	22000000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-2000000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	66000000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	25000000	USD
CY2020	us-gaap	Increase Decrease In Other Current Assets And Liabilities Net IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet	-44000000	USD
CY2019	us-gaap	Increase Decrease In Other Current Assets And Liabilities Net IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet	72000000	USD
CY2018	us-gaap	Increase Decrease In Other Current Assets And Liabilities Net IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet	-22000000	USD
CY2020	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	0	USD
CY2019	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	4000000	USD
CY2018	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	40000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1426000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1383000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1386000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1822000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1654000000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1586000000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	135000000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	235000000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	398000000	USD
CY2020	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	2000000	USD
CY2019	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	48000000	USD
CY2018	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	35000000	USD
CY2020	us-gaap	Payments For Proceeds From Removal Costs PaymentsForProceedsFromRemovalCosts	106000000	USD
CY2019	us-gaap	Payments For Proceeds From Removal Costs PaymentsForProceedsFromRemovalCosts	104000000	USD
CY2018	us-gaap	Payments For Proceeds From Removal Costs PaymentsForProceedsFromRemovalCosts	87000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2061000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1945000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2036000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1334000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1530000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1358000000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	342000000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	495000000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	526000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	15000000	USD
CY2018	awk	Proceedsfrom Term Loan ProceedsfromTermLoan	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	16000000	USD
CY2020	us-gaap	Repayments Of Construction Loans Payable RepaymentsOfConstructionLoansPayable	24000000	USD
CY2020	awk	Proceedsfrom Term Loan ProceedsfromTermLoan	500000000	USD
CY2019	awk	Proceedsfrom Term Loan ProceedsfromTermLoan	0	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt Maturing In Three Months Or Less ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess	-5000000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt Maturing In Three Months Or Less ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess	-178000000	USD
CY2018	us-gaap	Proceeds From Repayments Of Short Term Debt Maturing In Three Months Or Less ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess	60000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	183000000	USD
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	17000000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	11000000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	8000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	9000000	USD
CY2019	us-gaap	Repayments Of Construction Loans Payable RepaymentsOfConstructionLoansPayable	30000000	USD
CY2018	us-gaap	Repayments Of Construction Loans Payable RepaymentsOfConstructionLoansPayable	22000000	USD
CY2020	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	28000000	USD
CY2019	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	26000000	USD
CY2018	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	21000000	USD
CY2020	awk	Paymentsof Debt Issuance Costsand Make Whole Premium On Early Debt Redemption PaymentsofDebtIssuanceCostsandMakeWholePremiumOnEarlyDebtRedemption	15000000	USD
CY2019	awk	Paymentsof Debt Issuance Costsand Make Whole Premium On Early Debt Redemption PaymentsofDebtIssuanceCostsandMakeWholePremiumOnEarlyDebtRedemption	15000000	USD
CY2018	awk	Paymentsof Debt Issuance Costsand Make Whole Premium On Early Debt Redemption PaymentsofDebtIssuanceCostsandMakeWholePremiumOnEarlyDebtRedemption	22000000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	389000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	353000000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	319000000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	36000000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	45000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1120000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	494000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	726000000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	485000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-68000000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	76000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	91000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	159000000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	83000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	576000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	91000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	159000000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	382000000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	383000000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	332000000	USD
CY2020	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	2000000	USD
CY2019	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	4000000	USD
CY2018	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	0	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	38000000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	221000000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	7000000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	12000000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	235000000	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	181000000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	5385000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	567000000	USD
CY2018	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	219000000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	45000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	45000000	USD
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.82
CY2018	us-gaap	Dividends Cash DividendsCash	327000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	5864000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	621000000	USD
CY2019	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	38000000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	36000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-2000000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.00
CY2019	us-gaap	Dividends Cash DividendsCash	362000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	6121000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	709000000	USD
CY2020	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	37000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13000000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	2.20
CY2020	us-gaap	Dividends Cash DividendsCash	400000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	6454000000	USD
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-bottom:3pt;margin-top:18pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates</span></div><div style="margin-bottom:18pt;margin-top:3pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires that management make estimates, assumptions and judgments that could affect the Company’s financial condition, results of operations and cash flows. Actual results could differ from these estimates, assumptions and judgments. The Company considers its critical accounting estimates to include (i) the application of regulatory accounting principles and the related determination and estimation of regulatory assets and liabilities, (ii) revenue recognition and the estimates used in the calculation of unbilled revenue, (iii) accounting for income taxes, (iv) benefit plan assumptions and (v) the estimates and judgments used in determining loss contingencies. The Company’s critical accounting estimates that are particularly sensitive to change in the near term are amounts reported for regulatory assets and liabilities, income taxes, benefit plan assumptions and contingency-related obligations.</span></div>
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	547000000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	60000000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	29000000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	31000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	576000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	91000000	USD
CY2020Q4	awk	Repayment Of Advances For Construction RepaymentOfAdvancesForConstruction	23000000	USD
CY2019Q4	awk	Repayment Of Advances For Construction RepaymentOfAdvancesForConstruction	25000000	USD
CY2020	awk	Amortization Of Contributions In Aid Of Construction AmortizationOfContributionsInAidOfConstruction	32000000	USD
CY2019	awk	Amortization Of Contributions In Aid Of Construction AmortizationOfContributionsInAidOfConstruction	29000000	USD
CY2018	awk	Amortization Of Contributions In Aid Of Construction AmortizationOfContributionsInAidOfConstruction	28000000	USD
CY2020	awk	Contractwith Customer Payment Term From Billing Period ContractwithCustomerPaymentTermFromBillingPeriod	P30D
CY2020	us-gaap	Accrual For Environmental Loss Contingencies Payments1 AccrualForEnvironmentalLossContingenciesPayments1	1000000	USD
CY2020Q4	us-gaap	Accrual For Environmental Loss Contingencies AccrualForEnvironmentalLossContingencies	1000000	USD
CY2019Q4	us-gaap	Accrual For Environmental Loss Contingencies AccrualForEnvironmentalLossContingencies	2000000	USD
CY2020	us-gaap	Derivatives Reporting Of Derivative Activity DerivativesReportingOfDerivativeActivity	<div style="margin-bottom:3pt;margin-top:18pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Derivative Financial Instruments</span></div><div style="margin-bottom:12pt;margin-top:3pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company uses derivative financial instruments for purposes of hedging exposures to fluctuations in interest rates. These derivative contracts are entered into for periods consistent with the related underlying exposures and do not constitute positions independent of those exposures. The Company does not enter into derivative contracts for speculative purposes and does not use leveraged instruments.</span></div><div style="margin-bottom:12pt;margin-top:12pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">All derivatives are recognized on the balance sheet at fair value. On the date the derivative contract is entered into, the Company may designate the derivative as a hedge of the fair value of a recognized asset or liability (fair-value hedge) or a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability (cash-flow hedge).</span></div><div style="margin-bottom:12pt;margin-top:12pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Changes in the fair value of a fair-value hedge, along with the gain or loss on the underlying hedged item, are recorded in current-period earnings. The gains and losses on the effective portion of cash-flow hedges are recorded in other comprehensive income, until earnings are affected by the variability of cash flows. Any ineffective portion of designated cash-flow hedges is recognized in current-period earnings.</span></div>Cash flows from derivative contracts are included in net cash provided by operating activities on the Consolidated Statements of Cash Flows.
CY2020	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	ReclassificationsCertain reclassifications have been made to prior periods in the Consolidated Financial Statements and Notes to conform to the current presentation.
CY2020	awk	Public Utilities General Rate Case Authorizations PublicUtilitiesGeneralRateCaseAuthorizations	56000000	USD
CY2019	awk	Public Utilities General Rate Case Authorizations PublicUtilitiesGeneralRateCaseAuthorizations	45000000	USD
CY2018	awk	Public Utilities General Rate Case Authorizations PublicUtilitiesGeneralRateCaseAuthorizations	150000000	USD
CY2020	awk	Public Utilities Infrastructure Surcharge Authorizations PublicUtilitiesInfrastructureSurchargeAuthorizations	72000000	USD
CY2019	awk	Public Utilities Infrastructure Surcharge Authorizations PublicUtilitiesInfrastructureSurchargeAuthorizations	53000000	USD
CY2018	awk	Public Utilities Infrastructure Surcharge Authorizations PublicUtilitiesInfrastructureSurchargeAuthorizations	21000000	USD
CY2020Q4	awk	Regulatory Asset Earned Revenue Percentage RegulatoryAssetEarnedRevenuePercentage	0.50
CY2020Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	1127000000	USD
CY2019Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	1128000000	USD
CY2020Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	1770000000	USD
CY2019Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	1806000000	USD
CY2020Q4	awk	Numberof Proceedings Numberof Subsidiaries Effected Amortizationof Eadit NumberofProceedingsNumberofSubsidiariesEffectedAmortizationofEADIT	9	state
CY2020Q4	awk	Numberof Proceedings Numberof Subsidiaries Effected Pending Amortizationof Eadit NumberofProceedingsNumberofSubsidiariesEffectedPendingAmortizationofEADIT	5	state
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3743000000	USD
CY2020	us-gaap	Other Operating Income OtherOperatingIncome	34000000	USD
CY2020	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3777000000	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	39000000	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	13000000	USD
CY2018Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	14000000	USD
CY2020	awk	Contractwith Customer Asset Additions ContractwithCustomerAssetAdditions	60000000	USD
CY2020	us-gaap	Contract With Customer Asset Reclassified To Receivable ContractWithCustomerAssetReclassifiedToReceivable	34000000	USD
CY2019	awk	Contractwith Customer Asset Additions ContractwithCustomerAssetAdditions	27000000	USD
CY2019	us-gaap	Contract With Customer Asset Reclassified To Receivable ContractWithCustomerAssetReclassifiedToReceivable	28000000	USD
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	35000000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	27000000	USD
CY2018Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	20000000	USD
CY2020	awk	Contractwith Customer Liability Additions ContractwithCustomerLiabilityAdditions	120000000	USD
CY2020	awk	Contract With Customer Liability Revenue Recognized During The Period ContractWithCustomerLiabilityRevenueRecognizedDuringThePeriod	112000000	USD
CY2019	awk	Contractwith Customer Liability Additions ContractwithCustomerLiabilityAdditions	62000000	USD
CY2019	awk	Contract With Customer Liability Revenue Recognized During The Period ContractWithCustomerLiabilityRevenueRecognizedDuringThePeriod	55000000	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Property Plant And Equipment DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment	504000000	USD
CY2020Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation Current AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent	12000000	USD
CY2020Q4	awk	Disposal Group Including Discontinued Operation Regulatory Assets DisposalGroupIncludingDiscontinuedOperationRegulatoryAssets	64000000	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Goodwill1 DisposalGroupIncludingDiscontinuedOperationGoodwill1	39000000	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Other Assets DisposalGroupIncludingDiscontinuedOperationOtherAssets	10000000	USD
CY2020Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	629000000	USD
CY2020Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation Current LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent	14000000	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Deferred Tax Liabilities DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilities	69000000	USD
CY2020Q4	awk	Disposal Group Including Discontinued Operation Regulatory Liabilities DisposalGroupIncludingDiscontinuedOperationRegulatoryLiabilities	42000000	USD
CY2020Q4	us-gaap	Disposal Group Including Discontinued Operation Other Liabilities DisposalGroupIncludingDiscontinuedOperationOtherLiabilities	12000000	USD
CY2020Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	137000000	USD
CY2020Q4	us-gaap	Public Utilities Property Plant And Equipment Construction Work In Progress PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress	837000000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Construction Work In Progress PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress	801000000	USD
CY2020Q4	us-gaap	Public Utilities Property Plant And Equipment Plant In Service PublicUtilitiesPropertyPlantAndEquipmentPlantInService	25408000000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Plant In Service PublicUtilitiesPropertyPlantAndEquipmentPlantInService	23720000000	USD
CY2020Q4	awk	Public Non Utilities Property Plant And Equipment Plant For Internal Operations PublicNonUtilitiesPropertyPlantAndEquipmentPlantForInternalOperations	211000000	USD
CY2019Q4	awk	Public Non Utilities Property Plant And Equipment Plant For Internal Operations PublicNonUtilitiesPropertyPlantAndEquipmentPlantForInternalOperations	226000000	USD
CY2020	awk	Property Plant And Equipment Weighted Average Useful Life PropertyPlantAndEquipmentWeightedAverageUsefulLife	P8Y
CY2020Q4	awk	Disposal Group Including Discontinued Operation Public Non Utilities Property Plant And Equipment DisposalGroupIncludingDiscontinuedOperationPublicNonUtilitiesPropertyPlantAndEquipment	5000000	USD
CY2019Q4	awk	Disposal Group Including Discontinued Operation Public Non Utilities Property Plant And Equipment DisposalGroupIncludingDiscontinuedOperationPublicNonUtilitiesPropertyPlantAndEquipment	5000000	USD
CY2020Q4	us-gaap	Public Utilities Property Plant And Equipment Net PublicUtilitiesPropertyPlantAndEquipmentNet	25614000000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Net PublicUtilitiesPropertyPlantAndEquipmentNet	23941000000	USD
CY2020	us-gaap	Depreciation Depreciation	520000000	USD
CY2019	us-gaap	Depreciation Depreciation	508000000	USD
CY2018	us-gaap	Depreciation Depreciation	497000000	USD
CY2020	us-gaap	Public Utilities Property Plant And Equipment Disclosure Of Composite Depreciation Rate For Plants In Service PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService	0.0282
CY2019	us-gaap	Public Utilities Property Plant And Equipment Disclosure Of Composite Depreciation Rate For Plants In Service PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService	0.0296
CY2018	us-gaap	Public Utilities Property Plant And Equipment Disclosure Of Composite Depreciation Rate For Plants In Service PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService	0.0309
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	221000000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	235000000	USD
CY2019	us-gaap	Investment Tax Credit InvestmentTaxCredit	164000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	41000000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	45000000	USD
CY2017Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	42000000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	34000000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	28000000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	33000000	USD
CY2020	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	12000000	USD
CY2019	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	32000000	USD
CY2018	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	34000000	USD
CY2020	us-gaap	Allowance For Doubtful Accounts Receivable Recoveries AllowanceForDoubtfulAccountsReceivableRecoveries	0	USD
CY2019	us-gaap	Allowance For Doubtful Accounts Receivable Recoveries AllowanceForDoubtfulAccountsReceivableRecoveries	0	USD
CY2018	us-gaap	Allowance For Doubtful Accounts Receivable Recoveries AllowanceForDoubtfulAccountsReceivableRecoveries	4000000	USD
CY2020	awk	Accounts Receivable Allowance For Credit Loss Assets Held For Sale AccountsReceivableAllowanceForCreditLossAssetsHeldForSale	-3000000	USD
CY2019	awk	Accounts Receivable Allowance For Credit Loss Assets Held For Sale AccountsReceivableAllowanceForCreditLossAssetsHeldForSale	0	USD
CY2018	awk	Accounts Receivable Allowance For Credit Loss Assets Held For Sale AccountsReceivableAllowanceForCreditLossAssetsHeldForSale	0	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	60000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	41000000	USD
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	45000000	USD
CY2018Q4	us-gaap	Goodwill Gross GoodwillGross	4068000000	USD
CY2018Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	2493000000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	1575000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	3000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	3000000	USD
CY2019Q4	us-gaap	Disposal Group Including Discontinued Operation Goodwill1 DisposalGroupIncludingDiscontinuedOperationGoodwill1	39000000	USD
CY2019Q4	us-gaap	Disposal Group Including Discontinued Operation Goodwill1 DisposalGroupIncludingDiscontinuedOperationGoodwill1	39000000	USD
CY2019Q4	us-gaap	Goodwill Gross GoodwillGross	3941000000	USD
CY2019Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	2440000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	1501000000	USD
CY2020	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	5000000	USD
CY2020	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	5000000	USD
CY2020	awk	Goodwill Purchase Accounting Adjustments Cost GoodwillPurchaseAccountingAdjustmentsCost	-2000000	USD
CY2020	awk	Goodwill Purchase Accounting Adjustments Cost GoodwillPurchaseAccountingAdjustmentsCost	-2000000	USD
CY2020Q4	us-gaap	Goodwill Gross GoodwillGross	3944000000	USD
CY2020Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	2440000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	1504000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	3000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	14000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	10000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	8000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	6000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	5000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	4000000	USD
CY2020	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	0	shares
CY2019	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	400000	shares
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	36000000	USD
CY2020Q4	us-gaap	Stock Repurchase Program Remaining Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased	5100000	shares
CY2019	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-5000000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-3000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-2000000	USD
CY2020	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-16000000	USD
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-3000000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	389000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	353000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-13000000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	319000000	USD
CY2020Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.55
CY2019Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.455
CY2020Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.55
CY2019Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.455
CY2020Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.55
CY2019Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2018Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.455
CY2020Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.50
CY2019Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.455
CY2018Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.415
CY2020Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.55
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	21000000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17000000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16000000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4000000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5000000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	16000000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	13000000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	11000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	0	USD
CY2020	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	0	USD
CY2018	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	0	USD
CY2020Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	9688000000	USD
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	8692000000	USD
CY2020Q4	awk	Debt Instrument Unamortized Discount Premium Fair Value Net DebtInstrumentUnamortizedDiscountPremiumFairValueNet	-4000000	USD
CY2019Q4	awk	Debt Instrument Unamortized Discount Premium Fair Value Net DebtInstrumentUnamortizedDiscountPremiumFairValueNet	1000000	USD
CY2020Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	22000000	USD
CY2019Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	21000000	USD
CY2020Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	329000000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	28000000	USD
CY2020Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	9333000000	USD
CY2019Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	8644000000	USD
CY2020Q4	awk	Redeemable Debt Amount Outstanding RedeemableDebtAmountOutstanding	868000000	USD
CY2020Q4	us-gaap	Debt Weighted Average Interest Rate DebtWeightedAverageInterestRate	0.0185
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	329000000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	14000000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	356000000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	474000000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	597000000	USD
CY2020Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	7918000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1334000000	USD
CY2020Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	15000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Maximum Borrowing Capacity CommercialPaperAndLineOfCreditFacilityMaximumBorrowingCapacity	2250000000	USD
CY2019	awk	Ineffectiveness Recognized On Hedge Instruments IneffectivenessRecognizedOnHedgeInstruments	0	USD
CY2020	awk	Ineffectiveness Recognized On Hedge Instruments IneffectivenessRecognizedOnHedgeInstruments	0	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Maximum Borrowing Capacity CommercialPaperAndLineOfCreditFacilityMaximumBorrowingCapacity	2250000000	USD
CY2020Q4	awk	Commercial Paper Outstanding CommercialPaperOutstanding	786000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Maximum Borrowing Capacity CommercialPaperAndLineOfCreditFacilityMaximumBorrowingCapacity	2250000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Remaining Borrowing Capacity CommercialPaperAndLineOfCreditFacilityRemainingBorrowingCapacity	1390000000	USD
CY2020Q4	awk	Commercial Paper Maximum Borrowing Capacity CommercialPaperMaximumBorrowingCapacity	2100000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Maximum Borrowing Capacity CommercialPaperAndLineOfCreditFacilityMaximumBorrowingCapacity	2250000000	USD
CY2020Q4	awk	Commercial Paper Outstanding CommercialPaperOutstanding	786000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Outstanding CommercialPaperAndLineOfCreditFacilityOutstanding	862000000	USD
CY2020Q4	awk	Required Ratio Of Indebtedness To Net Capital1 RequiredRatioOfIndebtednessToNetCapital1	0.70
CY2020Q4	awk	Commercial Paper Remaining Borrowing Capacity CommercialPaperRemainingBorrowingCapacity	1314000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Remaining Borrowing Capacity CommercialPaperAndLineOfCreditFacilityRemainingBorrowingCapacity	1388000000	USD
CY2020Q4	awk	Commercial Paper And Line Of Credit Facility Remaining Borrowing Capacity CommercialPaperAndLineOfCreditFacilityRemainingBorrowingCapacity	1390000000	USD
CY2019Q4	awk	Commercial Paper Maximum Borrowing Capacity CommercialPaperMaximumBorrowingCapacity	2100000000	USD
CY2019Q4	awk	Commercial Paper And Line Of Credit Facility Maximum Borrowing Capacity CommercialPaperAndLineOfCreditFacilityMaximumBorrowingCapacity	2250000000	USD
CY2019Q4	awk	Commercial Paper Outstanding CommercialPaperOutstanding	786000000	USD
CY2019Q4	awk	Commercial Paper And Line Of Credit Facility Outstanding CommercialPaperAndLineOfCreditFacilityOutstanding	862000000	USD
CY2019Q4	awk	Commercial Paper Remaining Borrowing Capacity CommercialPaperRemainingBorrowingCapacity	1314000000	USD
CY2019Q4	awk	Commercial Paper And Line Of Credit Facility Remaining Borrowing Capacity CommercialPaperAndLineOfCreditFacilityRemainingBorrowingCapacity	1388000000	USD
CY2019Q4	awk	Commercial Paper And Line Of Credit Facility Remaining Borrowing Capacity CommercialPaperAndLineOfCreditFacilityRemainingBorrowingCapacity	1390000000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	547000000	USD
CY2020Q4	awk	Cash Cash Equivalents And Short Term Debt Liquidity CashCashEquivalentsAndShortTermDebtLiquidity	1935000000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	60000000	USD
CY2019Q4	awk	Cash Cash Equivalents And Short Term Debt Liquidity CashCashEquivalentsAndShortTermDebtLiquidity	1448000000	USD
CY2020	awk	Property And Capital Stock Tax PropertyAndCapitalStockTax	140000000	USD
CY2019	awk	Property And Capital Stock Tax PropertyAndCapitalStockTax	124000000	USD
CY2018	awk	Property And Capital Stock Tax PropertyAndCapitalStockTax	120000000	USD
CY2020	awk	Gross Receipts And Franchise Tax GrossReceiptsAndFranchiseTax	116000000	USD
CY2019	awk	Gross Receipts And Franchise Tax GrossReceiptsAndFranchiseTax	110000000	USD
CY2018	awk	Gross Receipts And Franchise Tax GrossReceiptsAndFranchiseTax	112000000	USD
CY2020	awk	Payroll Tax PayrollTax	36000000	USD
CY2019	awk	Payroll Tax PayrollTax	35000000	USD
CY2018	awk	Payroll Tax PayrollTax	33000000	USD
CY2020	us-gaap	Taxes Other TaxesOther	11000000	USD
CY2019	us-gaap	Taxes Other TaxesOther	11000000	USD
CY2018	us-gaap	Taxes Other TaxesOther	12000000	USD
CY2020	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	303000000	USD
CY2019	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	280000000	USD
CY2018	us-gaap	Utilities Operating Expense Taxes UtilitiesOperatingExpenseTaxes	277000000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	8000000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	4000000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	26000000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	1000000	USD
CY2020	us-gaap	Current Federal State And Local Tax Expense Benefit CurrentFederalStateAndLocalTaxExpenseBenefit	8000000	USD
CY2019	us-gaap	Current Federal State And Local Tax Expense Benefit CurrentFederalStateAndLocalTaxExpenseBenefit	4000000	USD
CY2018	us-gaap	Current Federal State And Local Tax Expense Benefit CurrentFederalStateAndLocalTaxExpenseBenefit	27000000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	49000000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	54000000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	33000000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	159000000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	155000000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	163000000	USD
CY2020	awk	Amortization Of Deferred Investment Tax Credits AmortizationOfDeferredInvestmentTaxCredits	-1000000	USD
CY2019	awk	Amortization Of Deferred Investment Tax Credits AmortizationOfDeferredInvestmentTaxCredits	-1000000	USD
CY2018	awk	Amortization Of Deferred Investment Tax Credits AmortizationOfDeferredInvestmentTaxCredits	-1000000	USD
CY2020	us-gaap	Deferred Federal State And Local Tax Expense Benefit DeferredFederalStateAndLocalTaxExpenseBenefit	207000000	USD
CY2019	us-gaap	Deferred Federal State And Local Tax Expense Benefit DeferredFederalStateAndLocalTaxExpenseBenefit	208000000	USD
CY2018	us-gaap	Deferred Federal State And Local Tax Expense Benefit DeferredFederalStateAndLocalTaxExpenseBenefit	195000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	215000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	212000000	USD
CY2019	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	7000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	21000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	222000000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
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
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.048
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.054
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.055
CY2020	awk	Effective Income Tax Rate Reconciliation Excess Accumulated Deferred Income Taxes Percent EffectiveIncomeTaxRateReconciliationExcessAccumulatedDeferredIncomeTaxesPercent	-0.021
CY2019	awk	Effective Income Tax Rate Reconciliation Excess Accumulated Deferred Income Taxes Percent EffectiveIncomeTaxRateReconciliationExcessAccumulatedDeferredIncomeTaxesPercent	-0.009
CY2018	awk	Effective Income Tax Rate Reconciliation Excess Accumulated Deferred Income Taxes Percent EffectiveIncomeTaxRateReconciliationExcessAccumulatedDeferredIncomeTaxesPercent	0.015
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	-0.004
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	-0.001
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Reconciling Items Percent EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent	0.002
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.233
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.254
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.282
CY2020Q4	awk	Deferred Tax Assets Advances And Contributions DeferredTaxAssetsAdvancesAndContributions	424000000	USD
CY2019Q4	awk	Deferred Tax Assets Advances And Contributions DeferredTaxAssetsAdvancesAndContributions	410000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	65000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	136000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Regulatory Assets And Liabilities DeferredTaxAssetsRegulatoryAssetsAndLiabilities	329000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Regulatory Assets And Liabilities DeferredTaxAssetsRegulatoryAssetsAndLiabilities	335000000	USD
CY2020Q4	awk	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions And Other Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensionsAndOtherPostretirementBenefits	100000000	USD
CY2019Q4	awk	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions And Other Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensionsAndOtherPostretirementBenefits	94000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	165000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	151000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	1083000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	1126000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	19000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	21000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	1064000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	1105000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2913000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2760000000	USD
CY2020Q4	awk	Deferred Tax Liabilities Deferred Pension And Other Postretirement Benefits DeferredTaxLiabilitiesDeferredPensionAndOtherPostretirementBenefits	97000000	USD
CY2019Q4	awk	Deferred Tax Liabilities Deferred Pension And Other Postretirement Benefits DeferredTaxLiabilitiesDeferredPensionAndOtherPostretirementBenefits	77000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	216000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	207000000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	3226000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	3044000000	USD
CY2020Q4	awk	Deferred Income Tax Liabilities Assets Held For Sale DeferredIncomeTaxLiabilitiesAssetsHeldForSale	-69000000	USD
CY2019Q4	awk	Deferred Income Tax Liabilities Assets Held For Sale DeferredIncomeTaxLiabilitiesAssetsHeldForSale	-67000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	2093000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	1872000000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	97000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	17000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	4000000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	110000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	18000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	6000000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	122000000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	12000000	USD
CY2017Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	13000000	USD
CY2018	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	1000000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	14000000	USD
CY2020	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-2000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	19000000	USD
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	0.0525
CY2020Q4	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Projected Benefit Obligation DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation	2386000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Projected Benefit Obligation DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation	2161000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	1990000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	1748000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	2188000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	2018000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	1990000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	1748000000	USD
CY2020	awk	Reduction Of Expected Future Service Of Plan Participants ReductionOfExpectedFutureServiceOfPlanParticipants	0.10
CY2020	awk	Cumulative Gains Losses As Percentage Of Benefit Obligations Or Plan Assets CumulativeGainsLossesAsPercentageOfBenefitObligationsOrPlanAssets	0.10
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	0.0525
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	12000000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	12000000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	12000000	USD
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	0.0525
CY2020	awk	Defined Contribution Plan Additional Base Pay Cost DefinedContributionPlanAdditionalBasePayCost	15000000	USD
CY2019	awk	Defined Contribution Plan Additional Base Pay Cost DefinedContributionPlanAdditionalBasePayCost	13000000	USD
CY2018	awk	Defined Contribution Plan Additional Base Pay Cost DefinedContributionPlanAdditionalBasePayCost	11000000	USD
CY2020Q4	awk	Estimated Capital Expenditures Under Legal And Binding Contractual Obligations EstimatedCapitalExpendituresUnderLegalAndBindingContractualObligations	484000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On First Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary	66000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Second Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary	67000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Third Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary	66000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Fourth Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary	52000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Fifth Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary	52000000	USD
CY2020Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Due After Five Years UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears	618000000	USD
CY2020Q4	us-gaap	Loss Contingency Accrual At Carrying Value LossContingencyAccrualAtCarryingValue	10000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	709000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	621000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	567000000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	181000000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	181000000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	180000000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1000000	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	182000000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	181000000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	180000000	shares
CY2020Q4	awk	Preferred Stocks With Mandatory Redemption Requirements Carrying Amount PreferredStocksWithMandatoryRedemptionRequirementsCarryingAmount	5000000	USD
CY2020Q4	us-gaap	Mandatorily Redeemable Preferred Stock Fair Value Disclosure MandatorilyRedeemablePreferredStockFairValueDisclosure	7000000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	9656000000	USD
CY2020Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	11807000000	USD
CY2019Q4	awk	Preferred Stocks With Mandatory Redemption Requirements Carrying Amount PreferredStocksWithMandatoryRedemptionRequirementsCarryingAmount	7000000	USD
CY2019Q4	us-gaap	Mandatorily Redeemable Preferred Stock Fair Value Disclosure MandatorilyRedeemablePreferredStockFairValueDisclosure	9000000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	8664000000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	9770000000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	29000000	USD
CY2020Q4	awk	Rabbi Trust Investments RabbiTrustInvestments	19000000	USD
CY2020Q4	awk	Deposit Assets Fair Value DepositAssetsFairValue	4000000	USD
CY2020Q4	awk	Other Investments Fair Value Disclosure OtherInvestmentsFairValueDisclosure	11000000	USD
CY2020Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	63000000	USD
CY2020Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Obligations FairValueLiabilitiesMeasuredOnRecurringBasisObligations	24000000	USD
CY2019Q4	awk	Other Investments Fair Value Disclosure OtherInvestmentsFairValueDisclosure	8000000	USD
CY2020	awk	Operatingand Financing Lease Payments OperatingandFinancingLeasePayments	14000000	USD
CY2019Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	59000000	USD
CY2020Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	24000000	USD
CY2020Q4	us-gaap	Fair Value Net Asset Liability FairValueNetAssetLiability	39000000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	31000000	USD
CY2019Q4	awk	Rabbi Trust Investments RabbiTrustInvestments	17000000	USD
CY2019Q4	awk	Deposit Assets Fair Value DepositAssetsFairValue	3000000	USD
CY2019Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Obligations FairValueLiabilitiesMeasuredOnRecurringBasisObligations	21000000	USD
CY2019Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	21000000	USD
CY2019Q4	us-gaap	Fair Value Net Asset Liability FairValueNetAssetLiability	38000000	USD
CY2020Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	147000000	USD
CY2019Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	147000000	USD
CY2020	awk	Operatingand Financing Lease Expenses OperatingandFinancingLeaseExpenses	14000000	USD
CY2019	awk	Operatingand Financing Lease Expenses OperatingandFinancingLeaseExpenses	16000000	USD
CY2018	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	35000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	924000000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	2000000	USD
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P5Y
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P19Y
CY2020Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.12
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.04
CY2020Q4	awk	Lessee Operating And Financing Lease Liability Payments Due Year One LesseeOperatingAndFinancingLeaseLiabilityPaymentsDueYearOne	13000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Payments Due Year Two LesseeOperatingandFinancingLeaseLiabilityPaymentsDueYearTwo	12000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Payments Due Year Three LesseeOperatingandFinancingLeaseLiabilityPaymentsDueYearThree	8000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Payments Due Year Four LesseeOperatingandFinancingLeaseLiabilityPaymentsDueYearFour	7000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Payments Due Year Five LesseeOperatingandFinancingLeaseLiabilityPaymentsDueYearFive	7000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Payments Dueafter Year Five LesseeOperatingandFinancingLeaseLiabilityPaymentsDueafterYearFive	94000000	USD
CY2020Q4	awk	Lessee Operatingand Financing Lease Liability Undiscounted Excess Amount LesseeOperatingandFinancingLeaseLiabilityUndiscountedExcessAmount	49000000	USD
CY2020	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3777000000	USD
CY2020	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	604000000	USD
CY2020	us-gaap	Operating Expenses OperatingExpenses	2529000000	USD
CY2020	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-395000000	USD
CY2019	us-gaap	Operating Expenses OperatingExpenses	2440000000	USD
CY2020Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	263000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	215000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	709000000	USD
CY2020Q4	us-gaap	Assets Assets	24766000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1822000000	USD
CY2019	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3610000000	USD
CY2019	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	582000000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-382000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	833000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	212000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	621000000	USD
CY2019Q4	us-gaap	Assets Assets	22682000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1654000000	USD
CY2018	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	3440000000	USD
CY2018	us-gaap	Utilities Operating Expense Depreciation And Amortization UtilitiesOperatingExpenseDepreciationAndAmortization	545000000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	57000000	USD
CY2018	us-gaap	Operating Expenses OperatingExpenses	2338000000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-350000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	787000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	222000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	567000000	USD
CY2018Q4	us-gaap	Assets Assets	21223000000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1586000000	USD
CY2020Q1	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	844000000	USD
CY2020Q2	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	931000000	USD
CY2020Q3	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	1079000000	USD
CY2020Q4	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	923000000	USD
CY2020Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	239000000	USD
CY2020Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	313000000	USD
CY2020Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	433000000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	124000000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	176000000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	264000000	USD
CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	145000000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.69
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.97
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.46
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.80
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.68
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.97
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.46
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.80
CY2019Q1	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	813000000	USD
CY2019Q2	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	882000000	USD
CY2019Q3	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	1013000000	USD
CY2019Q4	us-gaap	Regulated And Unregulated Operating Revenue RegulatedAndUnregulatedOperatingRevenue	902000000	USD
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	238000000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	302000000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	406000000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	224000000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	113000000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	170000000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	240000000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	98000000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.62
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.94
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.33
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.54
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.62
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.94
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.33
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.54

Files In Submission

Name	View Source	Status
0001410636-21-000101-index-headers.html	Edgar Link	pending
0001410636-21-000101-index.html	Edgar Link	pending
0001410636-21-000101.txt	Edgar Link	pending
0001410636-21-000101-xbrl.zip	Edgar Link	pending
awk-20201231.htm	Edgar Link	pending
awk-20201231.xsd	Edgar Link	pending
awk-20201231_cal.xml	Edgar Link	unprocessable
awk-20201231_def.xml	Edgar Link	unprocessable
awk-20201231_g1.jpg	Edgar Link	pending
awk-20201231_g2.jpg	Edgar Link	pending
awk-20201231_g3.jpg	Edgar Link	pending
awk-20201231_g4.jpg	Edgar Link	pending
awk-20201231_htm.xml	Edgar Link	completed
awk-20201231_lab.xml	Edgar Link	unprocessable
awk-20201231_pre.xml	Edgar Link	unprocessable
awkheader2a.jpg	Edgar Link	pending
ex-109x12312020xbrucehauko.htm	Edgar Link	pending
ex-211x12312020xsubsidiari.htm	Edgar Link	pending
ex-221x12312020xguaranteed.htm	Edgar Link	pending
ex-231x12312020xconsentofi.htm	Edgar Link	pending
ex-311x12312020.htm	Edgar Link	pending
ex-312x12312020.htm	Edgar Link	pending
ex-321x12312020.htm	Edgar Link	pending
ex-322x12312020.htm	Edgar Link	pending
ex-420x12312020xdescriptio.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
image_21.jpg	Edgar Link	pending
image_41a.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R109.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R110.htm	Edgar Link	pending
R111.htm	Edgar Link	pending
R112.htm	Edgar Link	pending
R113.htm	Edgar Link	pending
R114.htm	Edgar Link	pending
R115.htm	Edgar Link	pending
R116.htm	Edgar Link	pending
R117.htm	Edgar Link	pending
R118.htm	Edgar Link	pending
R119.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R120.htm	Edgar Link	pending
R121.htm	Edgar Link	pending
R122.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$AWK
American Water Works Company, Inc. Stock $awk

2020 Q4 Form 10-K Financial Statement

#000141063621000101 Filed on February 24, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AWK American Water Works Company, Inc. Stock $awk

2020 Q4 Form 10-K Financial Statement

#000141063621000101 Filed on February 24, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AWK
American Water Works Company, Inc. Stock $awk