Long-Term Debt, Before Current Portion And Bonds Held by Company

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Secured and Unsecured Debt

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

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

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- 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

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
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-Topic 835
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Noncurrent portion of a debt security issued by a state, certain agencies or authorities, a local government, or development corporation to finance the construction of air- or water-pollution control facilities or sewage or solid waste disposal facilities pursuant to federal law. The bonds are backed by the credit of the beneficiary of the financing rather than the credit of the issuer.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Carrying value at the balance sheet date of the noncurrent portion of a financial instrument used to receive debt funding on a regular basis with original maturities ranging from 5-10 years.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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+ Details

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Period Type:	instant

- Definition

Amount of long-term debt classified as other, payable after one year or the operating cycle, if longer.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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Balance Type:	debit
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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 10
-Section S99
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Long-Term Debt - Schedule Of Long-Term Debt Instruments (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Secured Debt		$ 2,232,200	$ 2,092,200
Secured and Unsecured Debt		2,247,200	2,107,200
Unamortized debt discount		(632)	(710)
Unamortized Debt Issuance Expense		(14,498)	(14,256)
Total		2,232,070	2,092,234
Current portion of long-term debt		(250,000)	0
Long-term debt		$ 1,898,370	2,008,534
First Mortgage [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Secured Debt [Member]
Debt Instrument [Line Items]
Pollution Control Bonds		$ (83,700)	(83,700)
2032 \| Secured Debt [Member]
Debt Instrument [Line Items]
Pollution Control Bonds		66,700
2034 \| Secured Debt [Member]
Debt Instrument [Line Items]
Pollution Control Bonds		17,000
Avista Utilities [Member]
Debt Instrument [Line Items]
Secured Debt		$ 2,157,200	2,017,200
Avista Utilities [Member] \| 2022 [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2022
Debt Instrument, Interest Rate, Stated Percentage		5.13%
Secured Debt		$ 250,000	250,000
Avista Utilities [Member] \| 2023 7.18% - 7.54% \| Secured Debt [Member]
Debt Instrument [Line Items]
Maturity Year		2023
Medium-Term Notes, Noncurrent		$ 13,500	13,500
Avista Utilities [Member] \| 2023 7.18% - 7.54% \| Minimum [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.18%
Avista Utilities [Member] \| 2023 7.18% - 7.54% \| Maximum [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.54%
Avista Utilities [Member] \| 2028 \| Secured Debt [Member]
Debt Instrument [Line Items]
Maturity Year		2028
Debt Instrument, Interest Rate, Stated Percentage		6.37%
Medium-Term Notes, Noncurrent		$ 25,000	25,000
Avista Utilities [Member] \| 2032 \| Secured Debt [Member]
Debt Instrument [Line Items]
Maturity Year		2032
Pollution Control Bonds		$ 66,700	66,700
Avista Utilities [Member] \| 2034 \| Secured Debt [Member]
Debt Instrument [Line Items]
Maturity Year		2034
Pollution Control Bonds		$ 17,000	17,000
Avista Utilities [Member] \| 2035 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2035
Debt Instrument, Interest Rate, Stated Percentage		6.25%
Secured Debt		$ 150,000	150,000
Avista Utilities [Member] \| 2037 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2037
Debt Instrument, Interest Rate, Stated Percentage		5.70%
Secured Debt		$ 150,000	150,000
Avista Utilities [Member] \| 2040 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2040
Debt Instrument, Interest Rate, Stated Percentage		5.55%
Secured Debt		$ 35,000	35,000
Avista Utilities [Member] \| 2041 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2041
Debt Instrument, Interest Rate, Stated Percentage		4.45%
Secured Debt		$ 85,000	85,000
Avista Utilities [Member] \| 2044 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2044
Debt Instrument, Interest Rate, Stated Percentage		4.11%
Secured Debt		$ 60,000	60,000
Avista Utilities [Member] \| 2045 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2045
Debt Instrument, Interest Rate, Stated Percentage		4.37%
Secured Debt		$ 100,000	100,000
Avista Utilities [Member] \| 2047 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2047
Debt Instrument, Interest Rate, Stated Percentage		4.23%
Secured Debt		$ 80,000	80,000
Avista Utilities [Member] \| 2047 3.91% \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2047
Debt Instrument, Interest Rate, Stated Percentage		3.91%
Secured Debt		$ 90,000	90,000
Avista Utilities [Member] \| 2048 4.35% \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2048
Debt Instrument, Interest Rate, Stated Percentage		4.35%
Secured Debt		$ 375,000	375,000
Avista Utilities [Member] \| 2049 3.43% \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2049
Debt Instrument, Interest Rate, Stated Percentage		3.43%
Secured Debt		$ 180,000	180,000
Avista Utilities [Member] \| 2050 3.07% \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2050
Debt Instrument, Interest Rate, Stated Percentage		3.07%
Secured Debt		$ 165,000	165,000
Avista Utilities [Member] \| 2051 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2051
Debt Instrument, Interest Rate, Stated Percentage		3.54%
Secured Debt		$ 175,000	175,000
Avista Utilities [Member] \| 2.90% Due in 2051 [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year	2051	2051
Debt Instrument, Interest Rate, Stated Percentage	2.90%	2.90%
Secured Debt		$ 140,000
Alaska Electric Light & Power [Member] \| 2044 \| First Mortgage [Member]
Debt Instrument [Line Items]
Maturity Year		2044
Debt Instrument, Interest Rate, Stated Percentage		4.54%
Secured Debt		$ 75,000	75,000
Alaska Energy Resources Company [Member] \| 2024 \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Maturity Year		2024
Debt Instrument, Interest Rate, Stated Percentage		3.44%
Unsecured Debt		$ 15,000	$ 15,000