Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 100,582	$ 25,730	$ 149,563	$ 68,831
Other Comprehensive Income (Loss):
Unrealized investment gains/(losses) - net of taxes	341	(1,222)	1,126	(1,292)
Reclassification adjustment for realized gains on investment securities included in net income - net of taxes	0	(10)	(2)	(11)
Reclassification adjustment for realized losses on investment securities net of taxes	462	0	462	0
Change in unfunded benefit obligation for pension and other postretirement benefit plans - net of taxes	112	183	223	367
Total other comprehensive loss	915	(1,049)	1,809	(936)
Comprehensive income	101,497	24,681	151,372	67,895
Comprehensive income attributable to noncontrolling interests	289	(73)	(193)	(833)
Comprehensive income attributable to Avista Corporation shareholders	$ 101,786	$ 24,608	$ 151,179	$ 67,062