Long-Term Debt and Capital Leases (Tables)

12 Months Ended

Dec. 31, 2016

Debt Instrument [Line Items]

Schedule of Capital Leases [Table Text Block]

The balances related to the Snettisham capital lease obligation as of December 31 were as follows (dollars in thousands):

	2016		2015
Capital lease obligation (1)	$	62,160	$	64,455
Capital lease asset (2)	71,007		71,007
Accumulated amortization of capital lease asset (2)	9,104		5,462

(1) The capital lease obligation amount is equal to the amount of AIDEA's revenue bonds outstanding.

(2) These amounts are included in utility plant in service on the Consolidated Balance Sheets.

Interest on the capital lease obligation and amortization of the capital lease asset are included in utility resource costs in the Consolidated Statements of Income and totaled the following amounts for the years ended December 31 (dollars in thousands):

	2016		2015
Interest on capital lease obligation	$	3,157	$	3,587
Amortization of capital lease asset	3,642		3,641

Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block]

	2017		2018		2019		2020		2021		Thereafter		Total
Principal	$	2,415	$	2,535	$	2,660	$	2,800	$	2,935	$	48,815	$	62,160
Interest	3,042		2,921		2,795		2,662		2,522		16,674		30,616
Total	$	5,457	$	5,456	$	5,455	$	5,462	$	5,457	$	65,489	$	92,776

Long-term Debt Outstanding

Maturity Year	Description	Interest Rate	2016			2015
Avista Corp. Secured Long-Term Debt
2016	First Mortgage Bonds (1)	0.84%	$	—		$	90,000
2018	First Mortgage Bonds	5.95%	250,000			250,000
2018	Secured Medium-Term Notes	7.39%-7.45%	22,500			22,500
2019	First Mortgage Bonds	5.45%	90,000			90,000
2020	First Mortgage Bonds	3.89%	52,000			52,000
2022	First Mortgage Bonds	5.13%	250,000			250,000
2023	Secured Medium-Term Notes	7.18%-7.54%	13,500			13,500
2028	Secured Medium-Term Notes	6.37%	25,000			25,000
2032	Secured Pollution Control Bonds (2)	(2)	66,700			66,700
2034	Secured Pollution Control Bonds (2)	(2)	17,000			17,000
2035	First Mortgage Bonds	6.25%	150,000			150,000
2037	First Mortgage Bonds	5.70%	150,000			150,000
2040	First Mortgage Bonds	5.55%	35,000			35,000
2041	First Mortgage Bonds	4.45%	85,000			85,000
2044	First Mortgage Bonds	4.11%	60,000			60,000
2045	First Mortgage Bonds	4.37%	100,000			100,000
2047	First Mortgage Bonds	4.23%	80,000			80,000
2051	First Mortgage Bonds (3)	3.54%	175,000			—
	Total Avista Corp. secured long-term debt		1,621,700			1,536,700
Alaska Electric Light and Power Company Secured Long-Term Debt
2044	First Mortgage Bonds	4.54%	75,000			75,000
	Total secured long-term debt		1,696,700			1,611,700
Alaska Energy and Resources Company Unsecured Long-Term Debt
2019	Unsecured Term Loan	3.85%	15,000			15,000
	Total secured and unsecured long-term debt		1,711,700			1,626,700
Other Long-Term Debt Components
	Capital lease obligations		65,435			68,601
	Settled interest rate swap derivatives (4)		—			(26,515		)
	Unamortized debt discount		(792		)	(956		)
	Unamortized long-term debt issuance costs		(10,639		)	(10,852		)
	Total		1,765,704			1,656,978
	Secured Pollution Control Bonds held by Avista Corporation (2)		(83,700		)	(83,700		)
	Current portion of long-term debt and capital leases		(3,287		)	(93,167		)
	Total long-term debt and capital leases		$	1,678,717		$	1,480,111

(1) In August 2016, Avista Corp. entered into a term loan agreement with a commercial bank in the amount of $70.0 million with a maturity date of December 30, 2016. Loans under this agreement were unsecured and had a variable annual interest rate. The Company borrowed the entire $70.0 million available under this agreement, which was used to repay a portion of the $90.0 million in first mortgage bonds that matured in August 2016. This term loan was subsequently repaid in full in December using the proceeds from the first mortgage bonds issued in December 2016 (discussed below).

(2) In December 2010, $66.7 million and $17.0 million of the City of Forsyth, Montana Pollution Control Revenue Refunding Bonds (Avista Corporation Colstrip Project) due in 2032 and 2034, respectively, which had been held by Avista Corp. since 2008 and 2009, respectively, were refunded by new bond issues (Series 2010A and Series 2010B). The new bonds were not offered to the public and were purchased by Avista Corp. due to market conditions. The Company expects that at a later date, subject to market conditions, these bonds may be remarketed to unaffiliated investors. So long as Avista Corp. is the holder of these bonds, the bonds will not be reflected as an asset or a liability on Avista Corp.'s Consolidated Balance Sheets.

(3) In December 2016, Avista Corp. issued and sold $175.0 million of 3.54 percent first mortgage bonds due in 2051 pursuant to a bond purchase agreement with institutional investors in the private placement market. The total net proceeds from the sale of the bonds were used to repay the $70.0 million term loan discussed above and to repay a portion of the borrowings outstanding under the Company’s $400.0 million committed line of credit. In connection with the execution of the bond purchase agreement, the Company cash-settled seven interest rate swap derivatives (notional aggregate amount of $125.0 million) and paid a total of $54.0 million.

(4) Prior to December 31, 2016, settled interest rate swap derivatives were included as part of long-term debt on the Consolidated Balance Sheets because they were considered similar to a debt discount or premium. During 2016, the Company reevaluated the presentation of settled interest rate swap derivatives and determined that since they are regulatory assets and liabilities that are being recovered through the ratemaking process, the more appropriate classification is as regulatory assets and liabilities rather than as a component of long-term debt. As such, as of December 31, 2016, the Company has included unamortized settled interest rate swap derivatives of $91.9 million in regulatory assets and $12.4 million in regulatory liabilities. The Company did not reclassify any amounts as of December 31, 2015 and prior because the amounts are not material to the financial statements. The increase in settled interest rate swap derivatives during 2016 is due to the cash settlement of interest rate swap derivatives discussed in detail above. There is no impact to the Consolidated Statements of Income and the Consolidated Statements of Cash Flows for any periods as a result of the balance sheet reclassification.

Long-term Debt Maturities

	2017		2018		2019		2020		2021		Thereafter		Total
Debt maturities	$	—	$	272,500	$	105,000	$	52,000	$	—	$	1,250,047	$	1,679,547