Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Appropriated Retained Earnings [Table Text Block]

The appropriated retained earnings amounts included in retained earnings were as follows as of December 31 (dollars in thousands):

	2019		2018
Appropriated retained earnings	$	43,151	$	39,346

Schedule of Goodwill [Table Text Block]

The changes in the carrying amount of goodwill are as follows (dollars in thousands):

	AEL&P		Other			Accumulated Impairment Losses			Total
Balance as of January 1, 2019	$	52,426	$	12,979		$	(7,733	)	$	57,672
Goodwill sold during the year	—		(12,979		)	7,733			(5,246		)
Balance as of December 31, 2019	$	52,426	$	—		$	—		$	52,426

Goodwill sold during the year relates to the sale of METALfx in April 2019. See Note 25 for further discussion. Accumulated impairment losses were attributable to METALfx, which was a part of the other businesses.

Regulatory Liability For Utility Plant Retirement Costs [Table Text Block]

The Company has recorded the amount of estimated retirement costs collected from customers (that do not represent legal or contractual obligations) and included them as a non-current regulatory liability on the Consolidated Balance Sheets in the following amounts as of December 31 (dollars in thousands):

	2019		2018
Regulatory liability for utility plant retirement costs	$	312,403	$	297,379

Schedule of Inventory, Current [Table Text Block]

Inventories of materials and supplies, fuel stock and stored natural gas are recorded at average cost for our regulated operations and the lower of cost or market for our non-regulated operations and consisted of the following as of December 31 (dollars in thousands):

	2019		2018
Materials and supplies	$	47,402	$	47,403
Fuel stock	4,875		4,869
Stored natural gas	14,306		11,609
Total	$	66,583	$	63,881

Financing Receivable, Allowance for Credit Loss [Table Text Block]

The following table presents the activity in the allowance for doubtful accounts during the years ended December 31 (dollars in thousands):

	2019			2018			2017
Allowance as of the beginning of the year	$	5,233		$	5,132		$	5,026
Additions expensed during the year	460			3,917			5,317
Net deductions	(3,274		)	(3,816		)	(5,211		)
Allowance as of the end of the year	$	2,419		$	5,233		$	5,132

Schedule of Other Nonoperating Income (Expense) [Table Text Block]

Other Expense (Income) - net consisted of the following items for the years ended December 31 (dollars in thousands):

	2019			2018			2017
Interest income	$	(2,587	)	$	(2,710	)	$	(2,162	)
Interest on regulatory deferrals	(1,460		)	(990		)	(1,288		)
Equity-related AFUDC	(6,585		)	(6,554		)	(6,669		)
Non-service portion of pension and other postretirement benefit expenses	8,899			5,156			7,670
Net (income) loss on investments	(14,299		)	5,369			4,160
Other expense (income)	1,104			1,187			(1,104		)
Total	$	(14,928	)	$	1,458		$	607

Share-based Payment Arrangement, Activity [Table Text Block]

The following table summarizes the number of grants, vested and unvested shares, earned shares (based on market metrics), and other pertinent information related to the Company's stock compensation awards for the years ended December 31:

	2019			2018			2017
Restricted Shares
Shares granted during the year	50,061			40,661			57,746
Shares vested during the year	(48,228		)	(53,352		)	(57,473		)
Unvested shares at end of year	93,351			91,998			106,053
Unrecognized compensation expense at end of year (in thousands)	$	2,054		$	1,964		$	1,853
TSR Awards
TSR shares granted during the year	99,214			80,724			114,390
TSR shares vested during the year	(106,858		)	(107,342		)	(107,649		)
TSR shares earned based on market metrics	—			—			158,262
Unvested TSR shares at end of year	178,035			187,172			218,507
Unrecognized compensation expense (in thousands)	$	3,377		$	3,706		$	2,849
CEPS Awards
CEPS shares granted during the year	49,609			40,329			57,223
CEPS shares vested during the year	(53,454		)	(53,699		)	(53,862		)
CEPS shares earned based on market metrics	106,908			30,102			41,502
Unvested CEPS shares at end of year	88,990			93,579			108,581
Unrecognized compensation expense (in thousands)	$	2,401		$	1,260		$	1,856

Share-based Payment Arrangement, Cost by Plan [Table Text Block]

The Company recorded stock-based compensation expense (included in other operating expenses) and income tax benefits in the Consolidated Statements of Income of the following amounts for the years ended December 31 (dollars in thousands):

	2019			2018		2017
Stock-based compensation expense	$	11,353		$	5,367	$	7,359
Income tax benefits (1)	2,384			1,127		2,576
Excess tax benefits (expenses) on settled share-based employee payments	(612		)	990		2,348

Effective Rate On Allowance For Funds Used During Construction [Table Text Block]

The effective AFUDC rate was the following for the years ended December 31:

	2019		2018		2017
Avista Utilities
Effective state AFUDC rate	7.39	%	7.43	%	7.29	%
Alaska Electric Light and Power Company
Effective AFUDC rate	8.96	%	9.04	%	9.48	%

Public Utility Property, Plant, and Equipment [Table Text Block]

For utility

operations, the ratio of depreciation provisions to average depreciable property was as follows for the years ended December 31:

	2019		2018		2017
Avista Utilities
Ratio of depreciation to average depreciable property	3.28	%	3.17	%	3.12	%
Alaska Electric Light and Power Company
Ratio of depreciation to average depreciable property	2.48	%	2.46	%	2.43	%

The average service lives for the following broad categories of utility plant in service are (in years):

	Avista Utilities	Alaska Electric Light and Power Company
Electric thermal/other production	35	40
Hydroelectric production	81	44
Electric transmission	50	41
Electric distribution	38	39
Natural gas distribution property	45	N/A
Other shorter-lived general plant	9	14

Net Utility Property

Net utility property consisted of the following as of December 31 (dollars in thousands):

	2019		2018
Utility plant in service	$	6,462,993	$	6,209,968
Construction work in progress	164,941		160,598
Total	6,627,934		6,370,566
Less: Accumulated depreciation and amortization	1,830,927		1,721,636
Total net utility property	$	4,797,007	$	4,648,930

Gross Property, Plant and Equipment

The gross balances of the major classifications of property, plant and equipment are detailed in the following table as of December 31 (dollars in thousands):

	2019		2018
Avista Utilities:
Electric production	$	1,445,017	$	1,426,961
Electric transmission	802,546		761,156
Electric distribution	1,847,273		1,726,410
Electric construction work-in-progress (CWIP) and other	350,331		341,041
Electric total	4,445,167		4,255,568
Natural gas underground storage	51,017		48,549
Natural gas distribution	1,203,186		1,118,720
Natural gas CWIP and other	81,245		76,488
Natural gas total	1,335,448		1,243,757
Common plant (including CWIP)	681,711		641,465
Total Avista Utilities	6,462,326		6,140,790
AEL&P:
Electric production	100,448		99,803
Electric transmission	22,000		21,347
Electric distribution	24,096		22,374
Electric production held under long-term capital lease (1)	—		71,007
Electric CWIP and other	9,539		7,072
Electric total	156,083		221,603
Common plant	9,525		8,173
Total AEL&P	165,608		229,776
Total gross utility property	6,627,934		6,370,566
Other (2)	28,195		39,145
Total	$	6,656,129	$	6,409,711

(1) At December 31, 2018, the finance lease ROU assets were included in "Net utility property" on the Consolidated Balance Sheet. Due to the adoption of ASC 842 on January 1, 2019, the Company has reclassified these amounts to "Other property and investments-net and other non-current assets" on the Consolidated Balance Sheet such that their presentation as of December 31, 2019 is consistent with operating leases.

(2)

Included in other property and investments-net and other non-current assets on the Consolidated Balance Sheets. Accumulated depreciation was $5.4 million as of December 31, 2019 and $12.4 million as of December 31, 2018 for the other businesses.