Selected Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2013

Selected Quarterly Financial Information [Abstract]

Summary of Quarterly Operations

	Three Months Ended
	March 31			June 30			September 30			December 31
2013
Operating revenues	$	482,906		$	352,048		$	335,875		$	447,676
Operating expenses	397,844			294,306			300,606			381,356
Income from operations	$	85,062		$	57,742		$	35,269		$	66,320
Net income	$	43,101		$	25,730		$	11,931		$	31,532
Net loss (income) attributable to noncontrolling interests	(760		)	(73		)	(518		)	134
Net income attributable to Avista Corporation shareholders	$	42,341		$	25,657		$	11,413		$	31,666
Outstanding common stock:
Weighted average, basic	59,866			59,937			59,994			60,037
Weighted average, diluted	59,898			59,962			60,032			60,087
Earnings per common share attributable to Avista Corporation shareholders, diluted	$	0.71		$	0.43		$	0.19		$	0.53
2012
Operating revenues	$	452,257		$	343,585		$	340,632		$	410,528
Operating expenses	375,863			297,565			314,023			369,481
Income from operations	$	76,394		$	46,020		$	26,609		$	41,047
Net income	$	38,213		$	18,532		$	5,962		$	16,093
Net loss (income) attributable to noncontrolling interests	175			(354		)	(176		)	(235		)
Net income attributable to Avista Corporation shareholders	$	38,388		$	18,178		$	5,786		$	15,858
Outstanding common stock:
Weighted average, basic	58,581			58,702			59,047			59,774
Weighted average, diluted	58,950			58,924			59,123			59,826
Earnings per common share attributable to Avista Corporation shareholders, diluted	$	0.65		$	0.31		$	0.10		$	0.26