Summary of Consolidation and Significant Accounting Policy (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021 USD ($) mi²	Jun. 30, 2021 USD ($) mi²	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Summary of Consolidation Policy
Allowance for Credit Losses, Beginning Balance				$ 20,080	$ 8,294
Provision for Credit Loss		$ 18,421	$ 9,762
Receivables Charged-Off	$ (5,060)		(7,157)
Allowance for Credit Loss, Ending Balance	$ 33,441	33,441	10,899
Variable Interest Entity [Line Items]
Bad Debt Deferral, COVID 19		$ 5,200
Subsidiaries [Member]
Summary of Consolidation Policy
Area of Service Territory (in sqmi) | mi²	6,000	6,000
Variable Interest Entity [Line Items]
Contract Length, PPA		20 years
Variable Interest Entity, Measure of Activity, Expense		$ 9,100
Variable Interest Entity, Payable	$ 2,400	$ 2,400
Subsidiaries [Member] | Tacoma LNG [Member]
Summary of Consolidation Policy
Jointly Owned Non-Utility Plant Share	43.00%	43.00%
Construction in Progress, Gross	$ 226,800	$ 226,800		207,700
Puget LNG [Member]
Summary of Consolidation Policy
Jointly Owned Non-Utility Plant Share	57.00%	57.00%
Construction in Progress, Gross	$ 234,400	$ 234,400		$ 231,600
Puget LNG [Member]
Summary of Consolidation Policy
Operating Costs and Expenses		$ 500	$ 700