CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 147,334	$ 129,488	$ 196,763
Other Comprehensive Income (Loss):
Change in unfunded benefit obligation for pension and other postretirement benefit plans - net of taxes of $888, $(1,095) and $(636), respectively	3,339	(4,119)	(2,393)
Total other comprehensive income (loss)	3,339	(4,119)	(2,393)
Comprehensive income	150,673	125,369	194,370
Comprehensive loss attributable to noncontrolling interests			216
Comprehensive income attributable to Avista Corporation shareholders	$ 150,673	$ 125,369	$ 194,586