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Regulatory Matters - Schedule of Decoupling and Earnings Sharing Mechanisms (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
WASHINGTON | Decoupling Surcharge [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory assets	$ 21,340,000	$ 22,440,000
WASHINGTON | Revenue Subject to Refund [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory Liabilities	0	0
IDAHO | Decoupling Surcharge [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory assets	1,202,000	2,549,000
IDAHO | Revenue Subject to Refund [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory Liabilities	(686,000)	(686,000)
OREGON | Revenue Subject to Refund [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory Liabilities	0	0
OREGON | Decoupling Surcharge [Member]
Scheduleof Decouplingand Earnings Sharing [Line Items]
Regulatory Liabilities	$ (1,262,000)	$ (739,000)

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[Line Items] for Schedule of Decoupling and Earnings Sharing [Table]

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The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
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-Topic 980
-SubTopic 405
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