Summary of Significant Accounting Policies (Details)				12 Months Ended
	Feb. 03, 2021	May 28, 2020	Dec. 19, 2017	Dec. 31, 2022 USD ($) mi²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jan. 01, 2018 USD ($)
Accounting Policies
Allowance for doubtful accounts				$ 41,962,000	$ 34,958,000
Monetized production tax credits				$ 0	45,600,000	$ 39,800,000
PTC, Operation Period				10 years
Bad Debt Deferral, COVID 19				$ 7,100,000	2,800,000
Excise and Sales Taxes				$ 292,800,000	$ 268,500,000	$ 240,800,000
Gas Transmission Equipment
Accounting Policies
Annual depreciation provision				2.90%	2.80%	2.90%
Common Plant
Accounting Policies
Annual depreciation provision				7.10%	6.80%	7.30%
Electricity, US Regulated [Member]
Accounting Policies
Annual depreciation provision				3.40%	3.40%	3.50%
Subsidiaries [Member]
Accounting Policies
Area of service territory (sqmi) | mi²				6,000
Allowance for doubtful accounts				$ 41,962,000	$ (34,958,000)
Public Utilities, Rate Case, Deferred Storm Costs Threshold							$ 10,000,000
Regulatory Asset, Amortization Period				1 year
Regulatory Liability, Amortization Period				1 year
Subsidiaries [Member] | Clearwater Wind Project
Accounting Policies
Variable Interest Entity, Measure of Activity, Expense				$ 5,700,000
Contract Length, PPA	25 years
Variable Interest Entity, Payable				2,500,000
Subsidiaries [Member] | Golden Hills Wind Farm
Accounting Policies
Variable Interest Entity, Measure of Activity, Expense				18,300,000
Contract Length, PPA		20 years
Variable Interest Entity, Payable				0
Subsidiaries [Member] | Skookumchuck Wind Energy Project
Accounting Policies
Variable Interest Entity, Measure of Activity, Expense				14,600,000	19,000,000
Variable Interest Entity, Payable				$ 1,400,000	2,700,000
Long-Term Purchase Commitment, Period				20 years
Puget LNG [Member]
Accounting Policies
Jointly Owned Non-Utility Plant Share				57.00%
Construction in Progress, Gross				$ 244,700,000
Operating Costs and Expenses				11,600,000	1,300,000	$ 600,000
Non-Utility Plant				$ 249,100,000
Tacoma LNG [Member]
Accounting Policies
Jointly Owned Non-Utility Plant Share				43.00%
Construction in Progress, Gross					$ 239,600,000
Public Utilities, Property, Plant and Equipment, Plant in Service				$ 245,700,000
Decoupling Mechanism [Member] | Electricity, US Regulated [Member] | Subsidiaries [Member] | Maximum
Accounting Policies
Public Utilities, Approved Rate Increase (Decrease), Percentage			3.00%
Decoupling Mechanism [Member] | Natural Gas, US Regulated [Member] | Subsidiaries [Member] | Maximum
Accounting Policies
Public Utilities, Approved Rate Increase (Decrease), Percentage			5.00%