Net payments from settlement of derivatives.

No definition available.

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Namespace Prefix:	ava_
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Balance Type:	credit
Period Type:	duration

- Definition

Number of interest rate swaps settled.

+ References

No definition available.

+ Details

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Namespace Prefix:	ava_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
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-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Balance Type:	na
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

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Balance Type:	na
Period Type:	duration

- Definition

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Balance Type:	credit
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- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
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-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Details

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Balance Type:
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- Details

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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_FirstMortgageMember
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- Details

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Long-Term Debt - Additional Information (Details) $ in Thousands		1 Months Ended	9 Months Ended
	Mar. 31, 2022 USD ($) Contract	Apr. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt			$ 399,856	$ 70,000
Repayment of long-term debt		$ 250,000
Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 400,000
4.00% Due in 2052 [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt	$ 400,000
Debt instrument interest rate percentage	4.00%
Debt instrument maturity year	2052
4.00% Due in 2052 [Member] \| Interest Rate Swap [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Number of interest rate swaps settled \| Contract	13
Notional amount	$ 140,000
Net payments from settlement of derivatives	$ 17,000