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WUTC (Details 5) - WUTC [Member] - Cascade Natural Gas [Member] - USD ($)	Jul. 01, 2021	Jun. 01, 2021	Jan. 08, 2021	Jul. 24, 2020	Jun. 19, 2020
Gas Distribution [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount					$ 13,800,000
Public Utilities, Requested Rate Increase (Decrease), Percentage					5.30%
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount			$ 7,400,000	$ 14,300,000
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage			2.80%	5.50%
Gas Distribution [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ (391,000)
Public Utilities, Approved Rate Increase (Decrease), Percentage	(0.20%)
Pending Rate Case [Member] | Pipeline Cost Recovery Mechanism [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 2,100,000
Public Utilities, Requested Rate Increase (Decrease), Percentage		0.80%

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