Property, Plant And Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

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.