Property, Plant And Equipment - Schedule of Major Classifications of Property, Plant And Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]
Construction work-in-progress (CWIP) and other	$ 164,147	$ 205,405
Total	7,725,835	7,371,985
Other Property	365,085	280,543
Total	7,742,466	7,389,803
Avista Utilities [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Total	7,545,007	7,199,017
Common Plant	744,173	740,339
Avista Utilities [Member] | Electricity [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Production	1,593,795	1,494,371
Transmission	994,709	945,624
Distribution	2,236,376	2,093,937
Construction work-in-progress (CWIP) and other	376,981	424,733
Total	5,201,861	4,958,665
Avista Utilities [Member] | Natural Gas [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	1,452,637	1,356,477
Construction work-in-progress (CWIP) and other	88,264	87,852
Total	1,598,973	1,500,013
Natural gas underground storage	58,072	55,684
Alaska Electric Light & Power [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Total	180,828	172,968
Common Plant	10,018	9,726
Alaska Electric Light & Power [Member] | Electricity [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Production	106,390	106,094
Transmission	22,856	22,691
Distribution	29,269	27,138
Construction work-in-progress (CWIP) and other	12,295	7,319
Total	170,810	163,242
Corporate and Other [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other Property	$ 16,631	$ 17,818