Short-Term Borrowings - Additional Information (Details) - USD ($)	1 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Jun. 30, 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
Bearing interest rate		12.00%
Credit agreement amount borrowed				$ 150,000,000
Letters of credit outstanding		$ 4,638,000	35,563,000
Line of credit facility, covenant terms, maximum debt to equity ratio		65.00%
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		$ 16,000,000	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, outstanding		$ 0	$ 0