Short-Term Borrowings - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2023	Apr. 30, 2014
Short-term Debt [Line Items]
Line of credit, outstanding		$ 0
Avista Utilities [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 500,000,000			$ 400,000,000
Line of credit facility, expiration date	2028-06
Line of credit facility additional expiration period	2 years
Line of credit facility, covenant terms, maximum debt to equity ratio	65.00%
Credit agreement amount borrowed			$ 150,000,000
Letters of credit outstanding	$ 4,700,000	35,563,000
Avista Utilities [Member] | Revolving credit agreement [Member]
Short-term Debt [Line Items]
Line of credit facility, termination date	2023-06
Current borrowings		100,000,000
Avista Utilities [Member] | 2022 Term Loan [Member]
Short-term Debt [Line Items]
Principal amount		$ 150,000,000
Maturity date		Mar. 30, 2023
Avista Utilities [Member] | Letter of Credit [Member]
Short-term Debt [Line Items]
Principal amount		$ 50,000,000
Letters of credit outstanding	$ 20,000,000	18,500,000
Alaska Electric Light & Power [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 25,000,000
Line of credit facility, expiration date	2028-06
Line of credit facility, covenant terms, maximum debt to equity ratio	67.50%
Line of credit, outstanding	$ 0	$ 0