Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Revenues:
Utility revenues	$ 430,537	$ 412,793
Other non-utility revenues	5,933	5,380
Total operating revenues	436,470	418,173
Utility operating expenses:
Resource costs	165,586	161,719
Other operating expenses	74,484	75,779
Depreciation and amortization	41,985	39,192
Taxes other than income taxes	32,662	29,385
Other non-utility operating expenses:
Other operating expenses	6,179	5,825
Depreciation and amortization	188	188
Total operating expenses	321,084	312,088
Income from operations	115,386	106,085
Interest expense	23,545	21,273
Interest expense to affiliated trusts	185	138
Capitalized interest	(724)	(914)
Other income-net	(3,101)	(2,422)
Income before income taxes	95,481	88,010
Income tax expense	33,344	30,345
Net income	62,137	57,665
Net income attributable to noncontrolling interests	(21)	(16)
Net income attributable to Avista Corporation shareholders	$ 62,116	$ 57,649
Weighted-average common shares outstanding (thousands), basic	64,362	62,605
Weighted-average common shares outstanding (thousands), diluted	64,469	62,907
Earnings per common share attributable to Avista Corporation shareholders:
Basic	$ 0.97	$ 0.92
Diluted	0.96	0.92
Common Stock, Dividends, Per Share, Cash Paid	$ 0.3575	$ 0.3425