Derivatives and Risk Management - Additional Information (Details)	9 Months Ended	12 Months Ended
Sep. 30, 2022 USD ($) MWh MMBTU	Dec. 31, 2021 USD ($) MWh MMBTU
Canadian [Member]
Derivative [Line Items]
Number of days Canadian currency prices are settled with U.S. dollars	60 days
Interest Rate Swap [Member]
Derivative [Line Items]
Cash collateral posted \| $	$ 0	$ 0
Letters of credit outstanding \| $	$ 0	$ 0
Purchase [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MWh	0	0
Purchase [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MMBTU	0	0
Purchase [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MWh	0	0
Purchase [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MMBTU	0	0
Sales [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MWh	0	0
Sales [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MMBTU	0	0
Sales [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MWh	0	0
Sales [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after five years \| MMBTU	0	0

Energy commodity derivatives expected to be settle after year five.

No definition available.

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Namespace Prefix:	ava_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of period currency prices are settled with domestic country currency.

+ References

No definition available.

+ Details

Name:	ava_NumberOfPeriodCurrencyPricesAreSettledWithDomesticCountryCurrency
Namespace Prefix:	ava_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	srt_StatementGeographicalAxis=country_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=ava_PurchaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=ava_PhysicalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_EnergyAxis=ava_ElectricDerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_EnergyAxis=ava_GasDerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=ava_FinancialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: