Selected Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2011

Selected Quarterly Financial Data [Abstract]

Summary Of Quarterly Operations

	Three Months Ended
	March 31			June 30			September 30			December 31
2011
Operating revenues	$	476,586		$	360,557		$	343,710		$	438,927
Operating expenses		391,761			305,033			308,832			378,532
Income from operations	$	84,825		$	55,524		$	34,878		$	60,395
Net income	$	42,403		$	23,528		$	11,637		$	25,971
Less: Net income attributable to noncontrolling interests		(485	)		(527	)		(935	)		(1,368	)
Net income attributable to Avista Corporation	$	41,918		$	23,001		$	10,702		$	24,603
Outstanding common stock:
Weighted average, basic		57,342			57,787			58,057			58,304
Weighted average, diluted		57,414			58,143			58,232			58,583
Earnings per common share attributable to Avista Corporation, diluted	$	0.73		$	0.39		$	0.18		$	0.42
2010
Operating revenues	$	456,415		$	360,733		$	367,172		$	374,420
Operating expenses		388,591			298,984			329,428			311,549
Income from operations	$	67,824		$	61,749		$	37,744		$	62,871
Net income	$	29,317		$	26,047		$	13,334		$	26,250
Less: Net income attributable to noncontrolling interests		(507	)		(507	)		(988	)		(521	)
Net income attributable to Avista Corporation	$	28,810		$	25,540		$	12,346		$	25,729
Outstanding common stock:
Weighted average, basic		54,869			55,031			55,616			56,835
Weighted average, diluted		55,115			55,231			55,801			57,126
Earnings per common share attributable to Avista Corporation, diluted	$	0.52		$	0.46		$	0.22		$	0.45