Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 90,172	$ 82,574
Accounts and notes receivable-less allowances of $44,598 and $44,309, respectively	202,820	221,343
Utility energy commodity derivative assets	13,925	3,022
Regulatory asset for utility derivatives	0	10,829
Investments and funds held for clients	95,851	96,688
Materials and supplies, fuel stock and natural gas stored	32,804	44,946
Deferred income taxes	24,288	24,788
Income taxes receivable	0	7,783
Other current assets	44,526	57,706
Total current assets	504,386	549,679
Net Utility Property:
Utility plant in service	4,341,383	4,290,464
Construction work in progress	157,330	160,323
Total	4,498,713	4,450,787
Less: Accumulated depreciation and amortization	1,271,082	1,248,362
Total net utility property	3,227,631	3,202,425
Other Non-current Assets:
Investment in exchange power-net	13,271	13,883
Investment in affiliated trusts	11,547	11,547
Goodwill	76,257	76,257
Intangible assets-net of accumulated amortization of $39,410 and $36,634, respectively	38,610	39,576
Long-term energy contract receivable of Spokane Energy	37,612	40,619
Other property and investments-net	48,171	58,555
Total other non-current assets	225,468	240,437
Deferred Charges:
Regulatory assets for deferred income tax	69,084	71,421
Regulatory assets for pensions and other postretirement benefits	155,205	156,984
Other regulatory assets	105,807	102,915
Non-current utility energy commodity derivative assets	3,545	854
Non-current regulatory asset for utility derivatives	11,654	23,258
Other deferred charges	13,298	13,950
Total deferred charges	358,593	369,382
Total assets	4,316,078	4,361,923
Current Liabilities:
Accounts payable	163,655	182,088
Client fund obligations	97,128	99,117
Current portion of long-term debt	372	358
Current portion of nonrecourse long-term debt of Spokane Energy	13,872	16,407
Short-term borrowings	111,000	171,000
Utility energy commodity derivative liabilities	3,360	10,875
Other current liabilities	180,834	145,495
Total current liabilities	570,221	625,340
Long-term debt	1,272,530	1,272,425
Nonrecourse long-term debt of Spokane Energy	0	1,431
Long-term debt to affiliated trusts	51,547	51,547
Long-term borrowings under committed line of credit	42,000	46,000
Regulatory liability for utility plant retirement costs	245,456	242,850
Pensions and other postretirement benefits	113,416	122,513
Deferred income taxes	534,540	535,343
Other non-current liabilities and deferred credits	119,295	130,318
Total liabilities	2,949,005	3,027,767
Commitments and Contingencies (See Notes to Consolidated Financial Statements)
Redeemable Noncontrolling Interests	15,960	15,889
Avista Corporation Stockholders’ Equity:
Common stock, no par value; 200,000,000 shares authorized; 60,161,140 and 60,076,752 shares outstanding, respectively	899,037	896,993
Accumulated other comprehensive loss	(4,925)	(5,819)
Retained earnings	436,370	407,092
Total Avista Corporation stockholders’ equity	1,330,482	1,298,266
Noncontrolling Interests	20,631	20,001
Total equity	1,351,113	1,318,267
Total liabilities and equity	$ 4,316,078	$ 4,361,923