Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Revenues:
Utility revenues	$ 1,402,195	$ 1,352,385	$ 1,441,522
Ecova revenues	176,761	155,664	137,848
Other non-utility revenues	39,549	38,953	40,410
Total operating revenues	1,618,505	1,547,002	1,619,780
Utility operating expenses:
Resource costs	689,586	693,127	790,048
Other operating expenses	276,228	276,780	261,926
Depreciation and amortization	117,174	112,091	105,629
Taxes other than income taxes	88,435	83,409	83,347
Ecova operating expenses:
Other operating expenses	148,023	139,173	109,738
Depreciation and amortization	15,434	13,519	7,193
Other non-utility operating expenses:
Other operating expenses	38,651	38,041	33,117
Depreciation and amortization	581	792	778
Total operating expenses	1,374,112	1,356,932	1,391,776
Income from operations	244,393	190,070	228,004
Interest expense	78,755	76,894	73,876
Interest expense to affiliated trusts	467	541	332
Capitalized interest	(3,676)	(2,401)	(2,942)
Other income-net	(6,677)	(5,025)	(3,433)
Income before income taxes	175,524	120,061	160,171
Income tax expense	63,230	41,261	56,632
Net income	112,294	78,800	103,539
Less: Net income attributable to noncontrolling interests	(1,217)	(590)	(3,315)
Net income attributable to Avista Corporation shareholders	$ 111,077	$ 78,210	$ 100,224
Weighted-average common shares outstanding (thousands), basic	59,960	59,028	57,872
Weighted-average common shares outstanding (thousands), diluted	59,997	59,201	58,092
Earnings per common share attributable to Avista Corporation shareholders:
Basic	$ 1.85	$ 1.32	$ 1.73
Diluted (usd per share)	$ 1.85	$ 1.32	$ 1.72