Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating Revenues:
Utility Revenues Excluding Alternative Revenue Programs	$ 288,513	$ 296,375	$ 1,006,003	$ 1,046,352
Revenue from Alternative Revenue Programs	606	(4,735)	(1,763)	(15,446)
Utility revenues	289,119	291,640	1,004,240	1,030,906
Other non-utility revenues	6,894	5,456	20,432	17,161
Total operating revenues	296,013	297,096	1,024,672	1,048,067
Utility operating expenses:
Resource costs	101,519	108,568	362,106	376,905
Other operating expenses	78,395	75,927	236,771	227,212
Acquisition costs	965	6,730	2,620	8,004
Depreciation and amortization	46,035	42,968	136,419	127,596
Taxes other than income taxes	25,101	23,269	81,526	79,733
Other non-utility operating expenses:
Other operating expenses	7,347	6,598	20,714	19,863
Depreciation and amortization	207	137	587	482
Total operating expenses	259,569	264,197	840,743	839,795
Income from operations	36,444	32,899	183,929	208,272
Interest expense	24,280	23,955	74,226	71,170
Interest expense to affiliated trusts	325	216	880	601
Capitalized interest	(1,217)	(899)	(3,324)	(2,513)
Other income-net	1,379	16	3,951	(851)
Income before income taxes	11,677	9,611	108,196	139,865
Income tax expense	1,548	5,153	17,467	51,548
Net income	10,129	4,458	90,729	88,317
Net income attributable to noncontrolling interests	(10)	(7)	(143)	21
Net income attributable to Avista Corporation shareholders	$ 10,119	$ 4,451	$ 90,586	$ 88,338
Weighted-average common shares outstanding (thousands), basic	65,688	64,412	65,668	64,392
Weighted-average common shares outstanding (thousands), diluted	66,026	64,892	65,980	64,638
Earnings per common share attributable to Avista Corporation shareholders:
Basic	$ 0.15	$ 0.07	$ 1.38	$ 1.37
Diluted	0.15	0.07	1.37	1.37
Common Stock, Dividends, Per Share, Cash Paid	$ 0.3725	$ 0.3575	$ 1.1175	$ 1.0725