Puget Energy (PSD) 10-Q 5 Nov 24 2024 Q3 Quarterly report Financial data

Cover

Cover	9 Months Ended
	Sep. 30, 2024 shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	1-16305
Entity Tax Identification Number	91-1969407
Entity Incorporation, State or Country Code	WA
Entity Address, Address Line One	355 110th Ave NE
Entity Address, City or Town	Bellevue
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98004
City Area Code	(425)
Local Phone Number	454-6363
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001085392
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding	200
Document Fiscal Year Focus	2024
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Registrant Name	PUGET ENERGY INC /WA
Subsidiaries [Member]
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	1-4393
Entity Tax Identification Number	91-0374630
Entity Incorporation, State or Country Code	WA
Entity Address, Address Line One	355 110th Ave NE
Entity Address, City or Town	Bellevue
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98004
City Area Code	(425)
Local Phone Number	454-6363
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000081100
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding	85,903,791
Document Fiscal Year Focus	2024
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Registrant Name	PUGET SOUND ENERGY, INC.

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating revenue:
Electric	$ 736,113	$ 770,406	$ 2,434,458	$ 2,461,205
Natural gas	182,737	160,233	1,017,096	947,631
Other	8,694	10,381	24,375	36,999
Total operating revenue	927,544	941,020	3,475,929	3,445,835
Energy costs:
Purchased electricity	250,822	250,384	892,436	817,739
Electric generation fuel	78,305	127,729	241,293	342,130
Residential exchange	(17,477)	(14,547)	(61,630)	(54,259)
Purchased natural gas	68,243	56,992	472,776	407,391
Unrealized (gain) loss on derivative instruments, net	108,979	(21,695)	131,712	201,230
Utility operations and maintenance	183,915	179,630	579,697	549,118
Non-utility expense and other	10,919	8,342	33,359	38,246
Depreciation and amortization	197,975	189,298	585,317	565,506
Conservation amortization	28,837	23,044	96,326	87,522
Taxes other than income taxes	75,869	72,616	291,226	298,456
Total operating expenses	986,387	871,793	3,262,512	3,253,079
Operating income (loss)	(58,843)	69,227	213,417	192,756
Other income (expense):
Other income	31,350	17,257	73,284	48,249
Other expense	(4,839)	(3,314)	(14,984)	(9,218)
Interest charges:
AFUDC	9,321	6,260	27,389	17,742
Interest expense	(111,642)	(96,635)	(320,926)	(280,068)
Income (loss) before income taxes	(134,653)	(7,205)	(21,820)	(30,539)
Income tax (benefit) expense	(13,545)	(1,908)	(1,545)	11,699
Net income (loss)	(121,108)	(5,297)	(20,275)	(42,238)
Subsidiaries [Member]
Operating revenue:
Electric	736,113	770,406	2,434,458	2,461,205
Natural gas	184,090	161,266	1,019,434	948,664
Other	40	933	222	16,271
Total operating revenue	920,243	932,605	3,454,114	3,426,140
Energy costs:
Purchased electricity	250,822	250,384	892,436	817,739
Electric generation fuel	78,305	127,729	241,293	342,130
Residential exchange	(17,477)	(14,547)	(61,630)	(54,259)
Purchased natural gas	68,243	56,992	472,776	407,391
Unrealized (gain) loss on derivative instruments, net	108,979	(21,695)	131,712	201,230
Utility operations and maintenance	183,915	179,630	579,697	549,118
Non-utility expense and other	5,719	3,342	15,912	18,076
Depreciation and amortization	196,298	187,622	580,304	560,480
Conservation amortization	28,837	23,044	96,326	87,522
Taxes other than income taxes	76,895	73,638	293,600	297,534
Total operating expenses	980,536	866,139	3,242,426	3,226,961
Operating income (loss)	(60,293)	66,466	211,688	199,179
Other income (expense):
Other income	30,651	17,131	71,073	46,300
Other expense	(4,839)	(3,314)	(14,984)	(9,218)
Interest charges:
AFUDC	9,321	6,260	27,389	17,742
Interest expense	(84,148)	(72,445)	(237,529)	(209,356)
Income (loss) before income taxes	(109,308)	14,098	57,637	44,647
Income tax (benefit) expense	(18,408)	695	3,922	2,244
Net income (loss)	$ (90,900)	$ 13,403	$ 53,715	$ 42,403

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net Income (loss)	$ (121,108)	$ (5,297)	$ (20,275)	$ (42,238)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized gain (loss) from pension and postretirement plans, net of tax	(1,727)	(517)	(4,679)	(8,260)
Other comprehensive income (loss)	(1,727)	(517)	(4,679)	(8,260)
Comprehensive income (loss)	(122,835)	(5,814)	(24,954)	(50,498)
Subsidiaries [Member]
Net Income (loss)	(90,900)	13,403	53,715	42,403
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized gain (loss) from pension and postretirement plans, net of tax	(1,174)	(38)	(3,080)	(6,787)
Amortization of treasury interest rate swaps to earnings, net of tax	97	97	290	289
Other comprehensive income (loss)	(1,077)	59	(2,790)	(6,498)
Comprehensive income (loss)	$ (91,977)	$ 13,462	$ 50,925	$ 35,905

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (459)	$ (137)	$ 1,088	$ (2,196)
Subsidiaries [Member]
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	(313)	(10)	1,512	(1,803)
Amortization of Financing Cash Flow Hedge Contracts to Earnings Tax	$ 25	$ 25	$ 76	$ 77

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Utility Plant [Abstract]
Public Utilities Property Plant And Equipment Electric Plant	$ 12,165,985	$ 11,304,995
Public Utilities Property Plant And Equipment Gas Plant	5,110,359	4,928,725
Public Utilities Property Plant And Equipment Common Plant	1,068,991	1,003,519
Less: Accumulated depreciation and amortization	(5,000,061)	(4,643,833)
Net utility plant	13,345,274	12,593,406
Other property and investments:
Goodwill	1,656,513	1,656,513
Other property and investments	308,805	312,353
Total other property and investments	1,965,318	1,968,866
Current assets:
Cash and cash equivalents	413,147	148,548
Restricted cash	66,016	66,027
Accounts receivable, net of allowance for doubtful accounts of $33,998 and $38,211, respectively	422,100	546,701
Unbilled revenue	174,522	243,342
Materials and supplies, at average cost	189,734	173,445
Fuel and natural gas inventory, at average cost	88,078	87,510
Unrealized gain on derivative instruments	31,373	74,225
GHG emission allowances	58,391	937
Prepaid expense and other	59,696	75,342
Power contract acquisition adjustment gain	6,287	16,358
Total current assets	1,509,344	1,432,435
Other long-term and regulatory assets:
Power cost adjustment mechanism	81,084	48,427
Regulatory assets related to power contracts	5,013	6,266
Other regulatory assets	993,032	1,163,551
Unrealized gain on derivative instruments	14,121	35,324
Power contract acquisition adjustment gain	27,596	30,566
Operating lease right-of-use asset	184,769	194,321
Other	281,278	259,291
Total other long-term and regulatory assets	1,586,893	1,737,746
Total assets	18,406,829	17,732,453
Common shareholder’s equity:
Common stock $0.01 par value, 1,000 shares authorized, 200 shares outstanding	0	0
Additional paid-in capital	3,816,332	3,523,532
Retained earnings	1,246,235	1,419,311
Accumulated other comprehensive income (loss), net of tax	12,860	17,539
Total common shareholder’s equity	5,075,427	4,960,382
Long-term debt:
First mortgage bonds and senior notes	5,862,000	5,062,000
Pollution control bonds	161,860	161,860
Long-term debt	1,600,000	2,000,000
Debt discount issuance costs and other	(186,165)	(187,218)
Total long-term debt	7,437,695	7,036,642
Total capitalization	12,513,122	11,997,024
Current liabilities:
Accounts payable	407,135	455,942
Short-term debt	371,100	598,100
Current maturities of long-term debt	400,000	0
Accrued expenses:
Taxes	100,428	102,627
Salaries and wages	61,695	68,726
Interest	99,006	63,829
Unrealized loss on derivative instruments	147,866	185,788
Power contract acquisition adjustment loss	1,152	1,487
Operating lease liabilities	22,517	21,629
Compliance Obligation, Current	58,391	937
Other	85,301	67,653
Total current liabilities	1,754,591	1,566,718
Other long-term and regulatory liabilities:
Deferred income taxes	959,653	950,229
Unrealized loss on derivative instruments	113,063	38,049
Purchased Gas Adjustment Liability, Long-term	60,483	132,082
Regulatory liabilities	1,113,318	1,022,457
Regulatory liability for deferred income taxes	733,969	760,961
Regulatory liabilities related to power contracts	33,883	46,924
Power contract acquisition adjustment loss	3,861	4,779
Operating lease liabilities	170,311	180,754
Finance lease liabilities	97,848	99,512
Compliance obligation	70,431	168,879
Other deferred credits	782,296	764,085
Total long-term and regulatory liabilities	4,139,116	4,168,711
Commitments and contingencies (Note 8)
Total capitalization and liabilities	18,406,829	17,732,453
Subsidiaries [Member]
Utility Plant [Abstract]
Public Utilities Property Plant And Equipment Electric Plant	13,888,041	13,043,559
Public Utilities Property Plant And Equipment Gas Plant	5,659,534	5,480,496
Public Utilities Property Plant And Equipment Common Plant	1,089,737	1,024,319
Less: Accumulated depreciation and amortization	(7,292,038)	(6,954,968)
Net utility plant	13,345,274	12,593,406
Other property and investments:
Other property and investments	70,673	69,808
Total other property and investments	70,673	69,808
Current assets:
Cash and cash equivalents	409,839	144,825
Restricted cash	66,016	66,027
Accounts receivable, net of allowance for doubtful accounts of $33,998 and $38,211, respectively	421,465	546,463
Unbilled revenue	174,522	243,342
Materials and supplies, at average cost	189,734	173,445
Fuel and natural gas inventory, at average cost	86,757	85,726
Unrealized gain on derivative instruments	31,373	74,225
GHG emission allowances	58,391	937
Prepaid expense and other	59,633	75,323
Total current assets	1,497,730	1,410,313
Other long-term and regulatory assets:
Power cost adjustment mechanism	81,084	48,427
Other regulatory assets	993,032	1,163,551
Unrealized gain on derivative instruments	14,121	35,324
Operating lease right-of-use asset	184,769	194,321
Other	279,126	256,617
Total other long-term and regulatory assets	1,552,132	1,698,240
Total assets	16,465,809	15,771,767
Common shareholder’s equity:
Common stock $0.01 par value, 1,000 shares authorized, 200 shares outstanding	859	859
Additional paid-in capital	3,927,905	3,635,105
Retained earnings	1,457,594	1,473,218
Accumulated other comprehensive income (loss), net of tax	(61,184)	(58,394)
Total common shareholder’s equity	5,325,174	5,050,788
Long-term debt:
First mortgage bonds and senior notes	5,862,000	5,062,000
Pollution control bonds	161,860	161,860
Debt discount issuance costs and other	(46,484)	(39,813)
Total long-term debt	5,977,376	5,184,047
Total capitalization	11,302,550	10,234,835
Current liabilities:
Accounts payable	407,136	457,965
Short-term debt	0	336,600
Accrued expenses:
Taxes	101,014	102,775
Salaries and wages	61,695	68,726
Interest	79,362	53,834
Unrealized loss on derivative instruments	147,866	185,788
Operating lease liabilities	22,517	21,629
Compliance Obligation, Current	58,391	937
Other	85,301	67,653
Total current liabilities	963,282	1,295,907
Other long-term and regulatory liabilities:
Deferred income taxes	1,062,990	1,078,847
Unrealized loss on derivative instruments	113,063	38,049
Purchased Gas Adjustment Liability, Long-term	60,483	132,082
Regulatory liabilities	1,112,054	1,021,193
Regulatory liability for deferred income taxes	734,617	761,621
Operating lease liabilities	170,311	180,754
Finance lease liabilities	97,848	99,512
Compliance obligation	70,431	168,879
Other deferred credits	778,180	760,088
Total long-term and regulatory liabilities	4,199,977	4,241,025
Commitments and contingencies (Note 8)
Total capitalization and liabilities	16,465,809	$ 15,771,767
Electric | Subsidiaries [Member]
Other long-term and regulatory liabilities:
Compliance obligation	$ 15,000

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
ASSETS
Construction work in progress	$ 1,717,323	$ 1,156,265
Current assets:
Allowance for doubtful accounts	33,998	38,211
Common shareholder’s equity:
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	1,717,323	1,156,265
Allowance for doubtful accounts	$ 33,998	$ 38,211
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000	1,000
Common Stock, Shares, Outstanding	200	200
Subsidiaries [Member]
ASSETS
Construction work in progress	$ 1,717,323	$ 1,156,265
Current assets:
Allowance for doubtful accounts	33,998	38,211
Common shareholder’s equity:
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	1,717,323	1,156,265
Allowance for doubtful accounts	$ 33,998	$ 38,211
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common Stock, Shares, Outstanding	85,903,791	85,903,791

CONSOLIDATED STATEMENTS OF COMM

CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDER’S EQUITY Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Subsidiaries [Member]	Subsidiaries [Member] Common Stock [Member]	Subsidiaries [Member] Additional Paid-in Capital [Member]	Subsidiaries [Member] Retained Earnings [Member]	Subsidiaries [Member] AOCI Attributable to Parent [Member]
Beginning Balance (in shares) at Dec. 31, 2022		200					85,903,791
Beginning Balance at Dec. 31, 2022	$ 4,964,089	$ 0	$ 3,523,532	$ 1,465,331	$ (24,774)	$ 4,871,083	$ 859	$ 3,535,105	$ 1,438,163	$ (103,044)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(31)			(31)		27,535			27,535
Dividends, Common Stock	(28,133)			(28,133)		(28,002)			(28,002)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(658)				(658)	133				133
Ending Balance (in shares) at Mar. 31, 2023		200					85,903,791
Ending Balance at Mar. 31, 2023	4,935,267	$ 0	3,523,532	1,437,167	(25,432)	4,870,749	$ 859	3,535,105	1,437,696	(102,911)
Beginning Balance (in shares) at Dec. 31, 2022		200					85,903,791
Beginning Balance at Dec. 31, 2022	4,964,089	$ 0	3,523,532	1,465,331	(24,774)	4,871,083	$ 859	3,535,105	1,438,163	(103,044)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(42,238)					42,403
Investment from Parent	0					100,000
Ending Balance (in shares) at Sep. 30, 2023		200					85,903,791
Ending Balance at Sep. 30, 2023	4,859,871	$ 0	3,523,532	1,369,373	(33,034)	4,956,351	$ 859	3,635,105	1,429,929	(109,542)
Beginning Balance (in shares) at Mar. 31, 2023		200					85,903,791
Beginning Balance at Mar. 31, 2023	4,935,267	$ 0	3,523,532	1,437,167	(25,432)	4,870,749	$ 859	3,535,105	1,437,696	(102,911)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(36,910)			(36,910)		1,465			1,465
Dividends, Common Stock	(14,292)			(14,292)		(22,000)			(22,000)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(7,085)				(7,085)	(6,690)				(6,690)
Ending Balance (in shares) at Jun. 30, 2023		200					85,903,791
Ending Balance at Jun. 30, 2023	4,876,980	$ 0	3,523,532	1,385,965	(32,517)	4,843,524	$ 859	3,535,105	1,417,161	(109,601)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(5,297)			(5,297)		13,403			13,403
Dividends, Common Stock	(11,295)			(11,295)		(635)			(635)
Investment from Parent						100,000		100,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(517)				(517)	59				59
Ending Balance (in shares) at Sep. 30, 2023		200					85,903,791
Ending Balance at Sep. 30, 2023	$ 4,859,871	$ 0	3,523,532	1,369,373	(33,034)	$ 4,956,351	$ 859	3,635,105	1,429,929	(109,542)
Beginning Balance (in shares) at Dec. 31, 2023	200	200				85,903,791	85,903,791
Beginning Balance at Dec. 31, 2023	$ 4,960,382	$ 0	3,523,532	1,419,311	17,539	$ 5,050,788	$ 859	3,635,105	1,473,218	(58,394)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	129,909			129,909		147,899			147,899
Dividends, Common Stock	(84,050)			(84,050)		(54,999)			(54,999)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(2,399)				(2,399)	(1,774)				(1,774)
Ending Balance (in shares) at Mar. 31, 2024		200					85,903,791
Ending Balance at Mar. 31, 2024	$ 5,003,842	$ 0	3,523,532	1,465,170	15,140	$ 5,141,914	$ 859	3,635,105	1,566,118	(60,168)
Beginning Balance (in shares) at Dec. 31, 2023	200	200				85,903,791	85,903,791
Beginning Balance at Dec. 31, 2023	$ 4,960,382	$ 0	3,523,532	1,419,311	17,539	$ 5,050,788	$ 859	3,635,105	1,473,218	(58,394)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(20,275)					53,715
Investment from Parent	$ 292,800					$ 292,800
Ending Balance (in shares) at Sep. 30, 2024	200	200				85,903,791	85,903,791
Ending Balance at Sep. 30, 2024	$ 5,075,427	$ 0	3,816,332	1,246,235	12,860	$ 5,325,174	$ 859	3,927,905	1,457,594	(61,184)
Beginning Balance (in shares) at Mar. 31, 2024		200					85,903,791
Beginning Balance at Mar. 31, 2024	5,003,842	$ 0	3,523,532	1,465,170	15,140	5,141,914	$ 859	3,635,105	1,566,118	(60,168)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(29,076)			(29,076)		(3,284)			(3,284)
Dividends, Common Stock	(56,891)			(56,891)		(14,340)			(14,340)
Investment from Parent	292,800		292,800			292,800		292,800
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(553)				(553)	61				61
Ending Balance (in shares) at Jun. 30, 2024		200					85,903,791
Ending Balance at Jun. 30, 2024	5,210,122	$ 0	3,816,332	1,379,203	14,587	5,417,151	$ 859	3,927,905	1,548,494	(60,107)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(121,108)			(121,108)		(90,900)			(90,900)
Dividends, Common Stock	(11,860)			(11,860)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (1,727)				(1,727)	$ (1,077)				(1,077)
Ending Balance (in shares) at Sep. 30, 2024	200	200				85,903,791	85,903,791
Ending Balance at Sep. 30, 2024	$ 5,075,427	$ 0	$ 3,816,332	$ 1,246,235	$ 12,860	$ 5,325,174	$ 859	$ 3,927,905	$ 1,457,594	$ (61,184)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities:
Net Income (loss)	$ (20,275)	$ (42,238)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	585,317	565,506
Conservation amortization	96,326	87,522
Deferred income taxes and tax credits, net	(18,656)	(83,024)
Net unrealized (gain) loss on derivative instruments	131,712	201,230
AFUDC - equity	(41,159)	(28,516)
Other non-cash	(12,603)	(11,312)
Regulatory assets and liabilities	(9,322)	134,755
Purchased gas adjustment	(71,600)	174,840
GHG emission allowances	(83,910)	(112,037)
Other long term assets and liabilities	(24,164)	(26,413)
Change in certain current assets and liabilities:
Accounts receivable and unbilled revenue	193,421	369,279
Materials and supplies	(16,289)	(20,219)
Fuel and natural gas inventory	(568)	(3,654)
Prepayments and other	41,225	8,180
Accounts payable	(77,349)	(289,853)
Taxes payable	(2,199)	25,998
Other	27,993	18,035
Net cash provided by (used in) operating activities	679,900	950,079
Investing activities:
Construction expenditures - excluding equity AFUDC	(1,143,829)	(875,359)
Other	1,874	14,020
Net cash provided by (used in) investing activities	(1,141,955)	(861,339)
Financing activities:
Change in short-term debt, net	(227,000)	(231,400)
Dividends paid	(152,801)	(53,720)
Investment from Parent	292,800	0
Proceeds from long-term debt and bonds issued	793,892	396,488
Other	19,752	16,445
Net cash provided by (used in) financing activities	726,643	127,813
Net increase (decrease) in cash, cash equivalents, and restricted cash	264,588	216,553
Cash, cash equivalents, and restricted cash at beginning of period	214,575	168,785
Cash, cash equivalents, and restricted cash at end of period	479,163	385,338
Supplemental cash flow information:
Cash payments for interest (net of capitalized interest)	246,252	227,186
Cash payments (refunds) for income taxes	37,065	50,707
Non-cash financing and investing activities:
Accounts payable for capital expenditures eliminated from cash flows	126,512	71,198
Asset Retirement Obligation, Revision of Estimate	18,957	0
Funding of pension liability	(18,000)	(18,000)
Subsidiaries [Member]
Operating activities:
Net Income (loss)	53,715	42,403
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	580,304	560,480
Conservation amortization	96,326	87,522
Deferred income taxes and tax credits, net	(44,451)	(127,228)
Net unrealized (gain) loss on derivative instruments	131,712	201,230
AFUDC - equity	(41,159)	(28,516)
Other non-cash	(20,482)	(19,190)
Regulatory assets and liabilities	(9,322)	134,755
Purchased gas adjustment	(71,600)	174,840
GHG emission allowances	(83,910)	(112,037)
Other long term assets and liabilities	(22,137)	(24,545)
Change in certain current assets and liabilities:
Accounts receivable and unbilled revenue	193,818	368,054
Materials and supplies	(16,289)	(20,219)
Fuel and natural gas inventory	(1,031)	(4,372)
Prepayments and other	41,269	8,256
Accounts payable	(79,371)	(288,415)
Taxes payable	(1,761)	27,100
Other	18,344	9,518
Net cash provided by (used in) operating activities	705,975	971,636
Investing activities:
Construction expenditures - excluding equity AFUDC	(1,143,346)	(875,139)
Other	1,874	14,020
Net cash provided by (used in) investing activities	(1,141,472)	(861,119)
Financing activities:
Change in short-term debt, net	(336,600)	(357,000)
Dividends paid	(69,339)	(50,637)
Investment from Parent	292,800	100,000
Proceeds from long-term debt and bonds issued	793,892	396,488
Other	19,747	16,457
Net cash provided by (used in) financing activities	700,500	105,308
Net increase (decrease) in cash, cash equivalents, and restricted cash	265,003	215,825
Cash, cash equivalents, and restricted cash at beginning of period	210,852	165,885
Cash, cash equivalents, and restricted cash at end of period	475,855	381,710
Supplemental cash flow information:
Cash payments for interest (net of capitalized interest)	180,382	172,869
Cash payments (refunds) for income taxes	67,888	84,357
Non-cash financing and investing activities:
Accounts payable for capital expenditures eliminated from cash flows	126,512	71,198
Asset Retirement Obligation, Revision of Estimate	18,957	0
Funding of pension liability	$ (18,000)	$ (18,000)

Summary of Consolidation and Si

Summary of Consolidation and Significant Accounting Policy	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation Puget Energy is an energy services holding company that owns PSE, which is a public utility incorporated in the state of Washington that furnishes electric and natural gas services in a territory covering approximately 6,000 square miles, primarily in the Puget Sound region. Puget Energy also has a wholly-owned non-regulated subsidiary, Puget LNG, which has the sole purpose of owning and operating the non-regulated activity of the Tacoma LNG facility. PSE and Puget LNG are considered related parties with similar ownership by Puget Energy. Therefore, capital and operating costs that are incurred by PSE and allocated to Puget LNG are related party transactions by nature. In 2009, Puget Holdings, owned by a consortium of long-term infrastructure investors, completed its merger with Puget Energy (the merger). As a result of the merger, all of Puget Energy’s common stock is indirectly owned by Puget Holdings. The acquisition of Puget Energy was accounted for in accordance with FASB ASC 805, “Business Combinations” (ASC 805), as of the date of the merger. ASC 805 requires the acquirer to recognize and measure identifiable assets acquired and liabilities assumed at fair value as of the merger date. The consolidated financial statements of Puget Energy reflect the accounts of Puget Energy and its subsidiaries. PSE’s consolidated financial statements include the accounts of PSE and its subsidiary. Puget Energy and PSE are collectively referred to herein as “the Company”. The consolidated financial statements are presented after elimination of all significant intercompany items and transactions. PSE’s consolidated financial statements continue to be accounted for on a historical basis and do not include any ASC 805, “Business Combinations” (ASC 805) purchase accounting adjustments. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Allowance for Credit Losses The Company measures expected credit losses on trade receivables on a collective basis by receivable type, which include electric retail receivables, natural gas retail receivables, and electric wholesale receivables. The estimate of expected credit losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. The following table presents the activity in the allowance for credit losses for accounts receivable for the nine months ended September 30, 2024 and 2023: Puget Energy and Nine Months (Dollars in Thousands) 2024 2023 Allowance for credit losses: Beginning balance $ 38,211 $ 41,962 Provision for credit loss expense 26,570 23,550 Receivables charged-off (30,783) (29,005) Total ending allowance balance 1 $ 33,998 $ 36,507 _____________ 1 $23.6 million and $12.2 million of provision related to balances of deferred costs specific to COVID-19 as of September 30, 2024 and 2023, respectively. Tacoma LNG Facility In February 2022, the Tacoma LNG facility at the Port of Tacoma completed commissioning and commenced commercial operations. In December 2019, the Puget Sound Clean Air Agency (PSCAA) issued the air quality permit for the facility, and the Pollution Hearings Control Board of Washington State upheld the approval following extended litigation. The Tacoma LNG facility provides peak-shaving services to PSE’s natural gas customers, and provides LNG as fuel to transportation customers, particularly in the marine market at a lower cost due to the facility's scale. The State of Washington Division II Court of Appeals upheld the permit issuance and in February 2024 denied the Puyallup Tribe of Indians' motion to reconsider. On March 22, 2024, a coalition of environmental organizations led by Advocates for a Cleaner Tacoma, petitioned the Washington Supreme Court to review portions of the Court of Appeals' decision and on March 25, 2024, the Puyallup Tribe of Indians also petitioned the Washington Supreme Court for review. On July 10, 2024, the court denied both parties' petition to review. Pursuant to an order by the Washington Commission, PSE will be allocated approximately 43.0% of common capital and operating costs, consistent with the regulated portion of the Tacoma LNG facility. The remaining 57.0% of common capital and operating costs of the Tacoma LNG facility will be allocated to Puget LNG. Per this allocation of costs, $236.1 million and $240.5 million of non-utility plant operating cost is reported in the Puget Energy "Other property and investments" line item as of September 30, 2024 and December 31, 2023, respectively. Additionally, $17.4 million and $20.3 million of operating costs are reported in the Puget Energy "Non-utility expense and other" financial statement line item for the nine months ended September 30, 2024, and September 30, 2023, respectively. Further, $230.5 million and $235.6 million of natural gas plant related to PSE’s portion of the Tacoma LNG facility is reported in the PSE “Utility plant - Natural gas plant” financial statement line item as of September 30, 2024 and December 31, 2023, respectively, as PSE is a regulated entity. Variable Interest Entities In April 2017, PSE entered into a power purchase agreement (PPA) with Skookumchuck Wind Energy Project, LLC (Skookumchuck) pursuant to which Skookumchuck would develop a wind generation facility and sell bundled energy and associated attributes, namely renewable energy certificates (RECs), to PSE over a term of 20 years. Skookumchuck commenced commercial operation in November 2020. In May 2020, PSE entered into a PPA with Golden Hills Wind Farm, LLC (Golden Hills) pursuant to which Golden Hills would develop a wind generation facility and sell bundled energy and associated attributes, namely RECs, to PSE over a term of 20 years. On April 29, 2022, Golden Hills commenced commercial operations. In February 2021, PSE entered into a PPA with Clearwater Wind Project, LLC (Clearwater) in which Clearwater would develop a wind generation facility and sell energy and associated attributes to PSE over a term of 25 years. On November 8, 2022, Clearwater commenced commercial operations. For each of the aforementioned PPAs, PSE has no equity investment in the generation facilities, but is the only customer of each facility. PSE has concluded that Skookumchuck, Golden Hills, and Clearwater represent variable interest entities (VIE) and that PSE is not the primary beneficiary of these VIEs since it does not control the commercial and operating activities of the facilities. Additionally, PSE does not have the obligation to absorb losses or receive benefits. As a result, PSE does not consolidate the VIEs. Purchased energy of $65.7 million and $64.2 million were recognized in purchased electricity on the Company's consolidated statements of income for the nine months ended September 30, 2024 and September 30, 2023, respectively. Additionally, $11.7 million and $14.6 million were included in accounts payable on the Company's balance sheet as of September 30, 2024 and December 31, 2023, respectively. For further information on the Company's accounting policies, see Part II, Item 8, Note 1, "Summary of Significant Accounting Policies" in the Company's Annual Report on Form 10-K for the year ended December 31, 2023.

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Guidance Reference Rate Reform In March 2020, the FASB issued ASU 2020-04, "Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ”. ASU 2020-04 provides temporary optional expedients and exceptions to the current guidance on contract modifications to ease the financial reporting burdens related to the expected market transition from LIBOR and other interbank offered rates to alternative reference rates. In December 2022, the FASB issued ASU 2022-06, "Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848" . ASU 2022-06 postpones the sunset date of Topic 848 from December 31, 2022 to December 31, 2024. As of September 30, 2024, the Company is not aware of any current agreements that reference LIBOR and thus, has not utilized any practical expedients. The Company continues to monitor whether any new agreements are entered into which reference LIBOR and if the expedients would be utilized through the allowed period of December 31, 2024. Accounting Pronouncements Issued but Not Yet Adopted Reportable Segment Disclosures In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures". ASU 2023-07 is intended to improve the disclosures for reportable segments and provide more detailed information about a reportable segment's expenses. This will require disclosure of significant segment expense categories, amounts for each reportable segment, disclosure of the title and position of the Chief Operating Decision Maker and how they use the measure of the segments profit or loss to assess performance and allocate resources. ASU 2023-07 will be effective for the Company in fiscal years beginning after December 15, 2023, and interim periods in fiscal years beginning after December 15, 2024. As the amendment contemplates changes in disclosures only, it is not expected to have a material impact on the Company's results of operations, cash flows, or consolidated balance sheets; however, the Company continues to assess the impacts of the amendment. Income Tax Disclosures In December 2023, the FASB issued ASU 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures". ASU 2023-09 will require disclosure of specific categories in a tabular rate reconciliation using both percentages and currency amounts, and provide additional information for reconciling items that meet a quantitative threshold. Further requirements include a qualitative description of the tax jurisdictions, an explanation of the reconciling items disclosed and disclosure regarding income taxes paid. ASU 2023-09 will eliminate the requirement to disclose the nature and estimate of range in unrecognized tax benefits and disclosures of the cumulative amount of each type of temporary difference when a deferred tax liability is not recognized. ASU 2023-09 will be effective for the Company in annual periods beginning after December 15, 2024. As the amendment contemplates changes in disclosures only, it is not expected to have a material impact on the Company's results of operations, cash flows, or consolidated balance sheets; however, the Company continues to assess the impacts of the amendment. Climate Related Disclosures In March 2024, the Securities and Exchange Commission (SEC) issued Final Rule S7-10-22, "The Enhancement and Standardization of Climate-Related Disclosures for Investors". Final Rule S7-10-22 will require disclosure for material climate-related risks; activities to adapt or mitigate climate-related risks; information regarding the roles of management and the board of directors in managing climate-related risks and information on climate-related targets or goals that are material to the business. Additionally, the final rules require disclosure of Scope 1 and/or Scope 2 GHG emissions on a phased-in basis by certain larger registrants with material emissions. PSE is a non-accelerated filer and Final Rule S7-10-22 does not require non-accelerated filers to disclose GHG emissions. The final rule was set to become effective May 28, 2024, however the SEC decided to stay implementation pending resolution of appeals. As currently drafted, Final Rule S7-10-22 will be effective for the Company in fiscal year 2027. The final rule impacts disclosures only, and thus is not expected to have a material impact on the Company's results of operations, cash flows, or consolidated balance sheets; however, the Company continues to assess the impacts of the final rule and the cost of compliance.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following tables present disaggregated revenue from contracts with customers, and other revenue by major source for the three and nine months ended September 30, 2024 and September 30, 2023: Puget Energy and Puget Sound Energy (Dollars in Thousands) Three Months Ended September 30, 2024 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 346,658 $ 78,517 $ — $ 425,175 Commercial 281,178 49,614 — 330,792 Industrial 31,634 3,818 — 35,452 Other 5,795 — — 5,795 Wholesale 68,485 — — 68,485 Transmission and transportation 7,297 6,434 — 13,731 Miscellaneous 2 11,250 41,464 8,694 61,408 Total revenue from contracts with customers $ 752,297 $ 179,847 $ 8,694 $ 940,838 Total other revenue 3 (16,184) 2,890 — (13,294) Total operating revenue $ 736,113 $ 182,737 $ 8,694 $ 927,544 _____________ 1 Other includes $8.7 million of Puget LNG revenues recorded at Puget Energy. 2 Miscellaneous natural gas revenue includes $41.2 million for the regulatory offset of CCA auction proceeds passed back to customers. 3 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Puget Energy and (Dollars in Thousands) Three Months Ended September 30, 2023 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 292,586 $ 91,393 $ — $ 383,979 Commercial 252,952 51,132 — 304,084 Industrial 29,794 4,003 — 33,797 Other 5,242 — — 5,242 Wholesale 174,039 — — 174,039 Transmission and transportation 10,403 4,540 — 14,943 Miscellaneous 7,895 (1,273) 10,381 17,003 Total revenue from contracts with customers $ 772,911 $ 149,795 $ 10,381 $ 933,087 Total other revenue 2 (2,505) 10,438 — 7,933 Total operating revenue $ 770,406 $ 160,233 $ 10,381 $ 941,020 _____________ 1 Other includes $9.4 million of Puget LNG revenues recorded at Puget Energy. 2 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Puget Energy and (Dollars in Thousands) Nine Months Ended September 30, 2024 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 1,207,130 $ 522,522 $ — $ 1,729,652 Commercial 857,267 250,068 — 1,107,335 Industrial 97,750 18,685 — 116,435 Other 17,585 — — 17,585 Wholesale 223,596 — — 223,596 Transmission and transportation 26,619 22,144 — 48,763 Miscellaneous 2 23,463 200,768 24,375 248,606 Total revenue from contracts with customers $ 2,453,410 $ 1,014,187 $ 24,375 $ 3,491,972 Total other revenue 3 (18,952) 2,909 — (16,043) Total operating revenue $ 2,434,458 $ 1,017,096 $ 24,375 $ 3,475,929 _____________ 1 Other includes $24.2 million of Puget LNG revenues recorded at Puget Energy. 2 Miscellaneous natural gas revenue includes $206.0 million for the regulatory offset of CCA auction proceeds passed back to customers. 3 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Puget Energy and (Dollars in Thousands) Nine Months Ended September 30, 2023 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 1,089,794 $ 612,458 $ — $ 1,702,252 Commercial 792,644 285,194 — 1,077,838 Industrial 92,161 21,286 — 113,447 Other 15,963 — — 15,963 Wholesale 376,191 — — 376,191 Transmission and transportation 35,516 15,493 — 51,009 Miscellaneous 18,870 (1,691) 36,999 54,178 Total revenue from contracts with customers $ 2,421,139 $ 932,740 $ 36,999 $ 3,390,878 Total other revenue 2 40,066 14,891 — 54,957 Total operating revenue $ 2,461,205 $ 947,631 $ 36,999 $ 3,445,835 _____________ 1 Other includes $20.7 million of Puget LNG revenues recorded at Puget Energy. 2 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Transaction Price Allocated to Remaining Performance Obligations In December 2020, Puget LNG entered into a contract with one customer where Puget LNG is selling LNG over a 10-year delivery period which began April 1, 2024. The contract requires the customer to purchase a minimum annual quantity even if the customer does not take delivery. The price of the LNG includes a fixed charge, a fuel charge that includes both a market index and fixed margin component and other variable consideration. The fixed transaction price is allocated to the remaining performance obligations which is determined by the fixed charge components multiplied by the outstanding minimum annual quantity. Based on management’s best estimate of commencement, the Company expects to recognize this revenue over the following time periods: Puget Energy (Dollars in Thousands) 2024 2025 2026 2027 2028 Thereafter Total Remaining performance obligations $ 5,238 $ 19,828 $ 19,454 $ 19,454 $ 19,454 $ 102,135 $ 185,563

Accounting for Derivative Instr

Accounting for Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accounting for Derivative Instruments and Hedging Activities	Accounting for Derivative Instruments and Hedging Activities PSE employs various energy portfolio optimization strategies but is not in the business of assuming risk for the purpose of realizing speculative trading revenue. The nature of serving regulated electric customers with its portfolio of owned and contracted electric generation resources exposes PSE and its customers to some volumetric and commodity price risks within the sharing mechanism of the Power Cost Adjustment. Therefore, wholesale market transactions and PSE's related hedging strategies are focused on reducing costs and risks where feasible, thus reducing volatility in costs in the portfolio. In order to manage its exposure to the variability in future cash flows for forecasted energy transactions, PSE utilizes a programmatic hedging strategy, which extends out three years. PSE's hedging strategy includes a risk-responsive component for the core natural gas portfolio, which utilizes quantitative risk-based measures with defined objectives to balance both portfolio risk and hedge costs. PSE's energy risk portfolio management function monitors and manages these risks using analytical models and tools. In order to manage risks effectively, PSE enters into forward physical electric and natural gas purchase and sale agreements, fixed-for-floating swap contracts, and commodity call/put options. Currently, the Company does not apply cash flow hedge accounting and therefore records all mark-to-market gains or losses through earnings. The Company manages its interest rate risk through the issuance of mostly fixed-rate debt with varied maturities. The Company utilizes internal cash from operations, borrowings under its commercial paper program and its credit facilities to meet short-term funding needs. The Company may enter into swap instruments or other financial hedge instruments to manage the interest rate risk associated with these debts. The following table presents the volumes, fair values and classification of the Company's derivative instruments recorded on the balance sheets: Puget Energy and September 30, 2024 December 31, 2023 (Dollars in Thousands) Volumes (millions) Assets 1 Liabilities 2 Volumes (millions) Assets 1 Liabilities 2 Electric portfolio derivatives * $ 39,585 $ 205,209 * $ 93,028 $ 126,939 Natural gas derivatives (MMBtus) 3 237 5,909 55,720 301 16,521 96,898 Total derivative contracts $ 45,494 $ 260,929 $ 109,549 $ 223,837 Current $ 31,373 $ 147,866 $ 74,225 $ 185,788 Long-term 14,121 113,063 35,324 38,049 Total derivative contracts $ 45,494 $ 260,929 $ 109,549 $ 223,837 _______________ 1 Balance sheet classification: Current and Long-term Unrealized gain on derivative instruments. 2 Balance sheet classification: Current and Long-term Unrealized loss on derivative instruments. 3 All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, “Regulated Operations,” due to the PGA mechanism. The net derivative asset or liability and offsetting regulatory liability or asset are related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. * Electric portfolio derivatives consist of electric generation fuel of 254.9 million MMBtu and purchased electricity of 13.4 million MWhs at September 30, 2024, and 315.6 million MMBtus and 2.3 million MWhs at December 31, 2023. It is the Company's policy to record all derivative transactions on a gross basis at the contract level without offsetting assets or liabilities. The Company generally enters into transactions using the following master agreements: WSPP agreements, which standardize physical power contracts; ISDA agreements, which standardize financial natural gas and electric contracts; and NAESB agreements, which standardize physical natural gas contracts. The Company believes that such agreements reduce credit risk exposure because such agreements provide for the netting and offsetting of monthly payments as well as the right of set-off in the event of counterparty default. The set-off provision can be used as a final settlement of accounts which extinguishes the mutual debts owed between the parties in exchange for a new net amount. For further details regarding the fair value of derivative instruments, see Note 5, "Fair Value Measurements," in the Combined Notes to Consolidated Financial Statements included in Item 1 of this report. The following tables present the potential effect of netting arrangements, including rights of set-off associated with the Company's derivative assets and liabilities: Puget Energy and At September 30, 2024 Gross Amount Recognized in the Statement of Financial Position 1 Gross Amounts Offset in the Statement of Financial Position Net of Amounts Presented in the Statement of Financial Position Gross Amounts Not Offset in the Statement of Financial Position (Dollars in Thousands) Commodity Contracts Cash Collateral Received/Posted Net Amount Assets: Energy derivative contracts $ 45,494 $ — $ 45,494 $ (39,821) $ — $ 5,673 Liabilities: Energy derivative contracts $ 260,929 $ — $ 260,929 $ (39,821) $ (6,030) $ 215,078 Puget Energy and At December 31, 2023 Gross Amount Recognized in the Statement of Financial Position 1 Gross Amounts Offset in the Statement of Financial Position Net of Amounts Presented in the Statement of Financial Position Gross Amounts Not Offset in the Statement of Financial Position (Dollars in Thousands) Commodity Contracts Cash Collateral Received/Posted Net Amount Assets: Energy derivative contracts $ 109,549 $ — $ 109,549 $ (82,206) $ — $ 27,343 Liabilities: Energy derivative contracts $ 223,837 $ — $ 223,837 $ (82,206) $ (84) $ 141,547 _______________ 1 All derivative contract deals are executed under ISDA, NAESB, and WSPP master agreements with right of set-off. The following table presents the effect and classification of the realized and unrealized gains (losses) of the Company's derivatives recorded on the statements of income: Puget Energy and Three Months Ended Nine Months Ended (Dollars in Thousands) Classification 2024 2023 2024 2023 Gas for power derivatives: Unrealized Unrealized gain (loss) on derivative instruments, net $ (6,807) $ 38,966 $ (3,550) $ (75,373) Realized Electric generation fuel (32,988) (23,442) (63,888) 51,253 Power derivatives: Unrealized Unrealized gain (loss) on derivative instruments, net (102,172) (17,271) (128,162) (125,857) Realized Purchased electricity (14,977) 25,076 (61,307) 72,208 Total gain (loss) recognized in income on derivatives $ (156,944) $ 23,329 $ (256,907) $ (77,769) The Company is exposed to credit risk primarily through buying and selling electricity and natural gas to serve its customers. Credit risk is the potential loss resulting from a counterparty's non-performance under an agreement. The Company manages credit risk with policies and procedures for, among other things, counterparty credit analysis, exposure measurement, and exposure monitoring and mitigation. The Company monitors counterparties for significant swings in credit default swap rates, credit rating changes by external rating agencies, ownership changes or financial distress. Where deemed appropriate, the Company may request collateral or other security from its counterparties to mitigate potential credit default losses. Criteria employed in this decision include, among other things, the perceived creditworthiness of the counterparty and the expected credit exposure. It is possible that volatility in energy commodity prices could cause the Company to have material credit risk exposure with one or more counterparties. If such counterparties fail to perform their obligations under one or more agreements, the Company could suffer a material financial loss. However, as of September 30, 2024, approximately 99.8% of the Company's energy portfolio exposure, excluding NPNS transactions, is with counterparties that are rated investment grade by rating agencies and 0.2% are either rated below investment grade or not rated by rating agencies. The Company assesses credit risk internally for counterparties that are not rated by the major rating agencies. The Company computes credit reserves at a master agreement level by counterparty. The Company considers external credit ratings and market factors in the determination of reserves, such as credit default swaps and bond spreads. The Company recognizes that external ratings may not always reflect how a market participant perceives a counterparty's risk of default. The Company uses both default factors published by Standard & Poor's and factors derived through analysis of market risk, which reflect the application of an industry standard recovery rate. The Company selects a default factor by counterparty at an aggregate master agreement level based on a weighted average default tenor for that counterparty's deals. The default tenor is determined by weighting the fair value and contract tenors for all deals for each counterparty to derive an average value. The default factor used is dependent upon whether the counterparty is in a net asset or a net liability position after applying the master agreement levels. The Company applies the counterparty's default factor to compute credit reserves for counterparties that are in a net asset position. The Company calculates a non-performance risk on its derivative liabilities by using its estimated incremental borrowing rate over the risk-free rate. Credit reserves are netted against the unrealized gain (loss) positions. The majority of the Company's derivative contracts are with financial institutions and other utilities operating within the Western Electricity Coordinating Council. PSE also transacts power futures contracts on the Intercontinental Exchange (ICE), and natural gas contracts on the ICE natural gas exchange (NGX) platform. Execution of contracts on ICE requires the daily posting of margin calls as collateral through a futures and clearing agent. As of September 30, 2024, PSE had cash posted as collateral of $9.7 million related to contracts executed on the ICE platform. As a condition of transacting on the ICE NGX platform as well as participating in the Washington state carbon allowance auctions, PSE maintains a standby letter of credit agreement with TD Bank. As of September 30, 2024, PSE had no cash posted with ICE NGX, and $4.1 million was issued under the standby letter of credit agreement in support of natural gas and carbon allowance purchases. PSE did not trigger any collateral requirements with any of its counterparties nor were any of PSE's counterparties required to post collateral resulting from credit rating downgrades during the nine months ended September 30, 2024. The following table presents the aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a liability position and the amount of additional collateral the Company could be required to post: Puget Energy and (Dollars in Thousands) At September 30, 2024 At December 31, 2023 Fair Value 1 Posted Contingent Fair Value 1 Posted Contingent Contingent Feature Liability Collateral Collateral Liability Collateral Collateral Credit rating 2 $ 112,218 $ — $ 112,218 $ 13,384 $ — $ 13,384 Requested credit for adequate assurance 31,565 — — 53,427 — — Forward value of contract 3 6,412 9,742 N/A 84 12,429 N/A Total $ 150,195 $ 9,742 $ 112,218 $ 66,895 $ 12,429 $ 13,384 _______________ 1 Represents the derivative fair value of contracts with contingent features for counterparties in net derivative liability positions. Excludes NPNS, accounts payable and accounts receivable. 2 Failure by PSE to maintain an investment grade credit rating from each of the major credit rating agencies provides counterparties a contractual right to demand collateral. 3 Collateral requirements may vary based on changes in the forward value of underlying transactions relative to contractually defined collateral thresholds.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements ASC 820 established a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy categorizes the inputs into three levels with the highest priority given to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority given to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are as follows: Level 1 - Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Level 1 primarily consists of financial instruments such as exchange-traded derivatives and listed equities. Equity securities that are also classified as cash equivalents are considered Level 1 if there are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 - Pricing inputs are other than quoted prices in active markets included in Level 1, which are either directly or indirectly observable as of the reporting date. Level 2 includes those financial instruments that are valued using models or other valuation methodologies. Instruments in this category include non-exchange-traded derivatives such as over-the-counter forwards and options. Level 3 - Pricing inputs include significant inputs that have little or no observability as of the reporting date. These inputs may be used with internally developed methodologies that result in management's best estimate of fair value. Financial assets and liabilities measured at fair value are classified in their entirety in the appropriate fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The Company's assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy. The Company primarily determines fair value measurements classified as Level 2 or Level 3 using a combination of the income and market valuation approaches. The process of determining the fair values is the responsibility of the derivative accounting department, which reports to the Controller and Principal Accounting Officer. Inputs used to estimate the fair value of forwards, swaps and options include market-price curves, contract terms and prices, credit-risk adjustments, and discount factors. Additionally, for options, the Black-Scholes option valuation model and implied market volatility curves are used. Inputs used to estimate fair value in industry-standard models are categorized as Level 2 inputs as substantially all assumptions and inputs are observable in active markets throughout the full term of the instruments. On a daily basis, the Company obtains quoted forward prices for the electric and natural gas markets from an independent external pricing service. The Company considers its electric and natural gas contracts as Level 2 derivative instruments as such contracts are commonly traded as over-the-counter forwards with indirectly observable price quotes. However, certain energy derivative instruments with maturity dates falling outside the range of observable price quotes or that are transacted at illiquid delivery locations are classified as Level 3 in the fair value hierarchy. Management's assessment is based on the trading activity in real-time and forward electric and natural gas markets. Each quarter, the Company confirms the validity of pricing-service quoted prices used to value Level 2 commodity contracts with the actual prices of commodity contracts entered into during the most recent quarter. The Company’s environmental compliance obligation is categorized in Level 2 of the fair value hierarchy and is measured at fair value using a market approach based on quoted prices from an independent pricing service. Assets and Liabilities with Estimated Fair Value The carrying values of cash and cash equivalents, restricted cash, and short-term debt as reported on the balance sheet are reasonable estimates of their fair value due to the short-term nature of these instruments and are classified as Level 1 in the fair value hierarchy. The carrying value of other investments of $45.1 million and $44.6 million at September 30, 2024 and December 31, 2023 respectively, are included in "Other property and investments" on the balance sheet. These values are also reasonable estimates of their fair value and classified as Level 2 in the fair value hierarchy as they are valued based on market rates for similar transactions. The fair value of the long-term notes was estimated using the discounted cash flow method with the U.S. Treasury yields and the Company's credit spreads as inputs, interpolating to the maturity date of each issue. The carrying values and estimated fair values were as follows: Puget Energy September 30, 2024 December 31, 2023 (Dollars in Thousands) Level Carrying Fair Carrying Fair Liabilities: Long-term debt (fixed-rate), net of discount 1 2 $ 7,437,695 $ 7,396,449 $ 7,036,642 $ 6,855,503 Total liabilities $ 7,437,695 $ 7,396,449 $ 7,036,642 $ 6,855,503 Puget Sound Energy September 30, 2024 December 31, 2023 (Dollars in Thousands) Level Carrying Fair Carrying Fair Liabilities: Long-term debt (fixed-rate), net of discount 2 2 $ 5,977,376 $ 5,869,739 $ 5,184,047 $ 5,007,483 Total liabilities $ 5,977,376 $ 5,869,739 $ 5,184,047 $ 5,007,483 _______________ 1 The carrying value includes debt issuances costs of $21.8 million and $21.0 million for September 30, 2024 and December 31, 2023, respectively, which are not included in fair value. 2 The carrying value includes debt issuances costs of $22.5 million and $21.2 million for September 30, 2024 and December 31, 2023, respectively, which are not included in fair value. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents the Company's financial assets and liabilities by level, within the fair value hierarchy, that were accounted for at fair value on a recurring basis: Puget Energy and Fair Value Fair Value (Dollars in Thousands) Level 2 Level 3 Total Level 2 Level 3 Total Assets: Electric derivative instruments $ 17,906 $ 21,679 $ 39,585 $ 42,254 $ 50,774 $ 93,028 Natural gas derivative instruments 3,304 2,605 5,909 11,647 4,874 16,521 Total assets $ 21,210 $ 24,284 $ 45,494 $ 53,901 $ 55,648 $ 109,549 Liabilities: Electric derivative instruments $ 95,060 $ 110,149 $ 205,209 $ 103,427 $ 23,512 $ 126,939 Natural gas derivative instruments 55,055 665 55,720 95,875 1,023 96,898 Compliance obligations 70,431 — 70,431 168,879 — 168,879 Total liabilities $ 220,546 $ 110,814 $ 331,360 $ 368,181 $ 24,535 $ 392,716 The following tables presents the Company's reconciliation of the changes in the fair value of Level 3 derivatives in the fair value hierarchy: Puget Energy and Three Months Ended September 30, (Dollars in Thousands) 2024 2023 Level 3 Roll-Forward Net Asset/(Liability) Electric Natural Gas Total Electric Natural Gas Total Balance at beginning of period $ 3,041 $ 2,022 $ 5,063 $ 57,907 $ 104 $ 58,011 Changes during period: Realized and unrealized energy derivatives: Included in earnings 1 (97,624) — (97,624) (12,551) — (12,551) Included in regulatory assets / liabilities — 1,217 1,217 — 3,808 3,808 Settlements 6,113 (1,299) 4,814 (9,752) (351) (10,103) Transferred into Level 3 — — — — — — Transferred out of Level 3 — — — — — — Balance at end of period $ (88,470) $ 1,940 $ (86,530) $ 35,604 $ 3,561 $ 39,165 Puget Energy and Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 Level 3 Roll-Forward Net Asset/(Liability) Electric Natural Gas Total Electric Natural Gas Total Balance at beginning of period $ 27,262 $ 3,851 $ 31,113 $ 116,078 $ (127) $ 115,951 Changes during period: Realized and unrealized energy derivatives: Included in earnings 2 (148,522) — (148,522) (47,613) — (47,613) Included in regulatory assets / liabilities — 1,741 1,741 — 3,852 3,852 Settlements 32,790 (3,652) 29,138 (33,078) (334) (33,412) Transferred into Level 3 — — — — — — Transferred out of Level 3 — — — 217 170 387 Balance at end of period $ (88,470) $ 1,940 $ (86,530) $ 35,604 $ 3,561 $ 39,165 _______________ 1 Income Statement locations: Unrealized gain (loss) on derivative instruments, net. Amounts include unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(90.9) million and $(16.1) million for the three months ended September 30, 2024 and 2023, respectively. 2 Income Statement locations: Unrealized gain (loss) on derivative instruments, net. Amounts include unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(112.4) million and $(25.9) million for the nine months ended September 30, 2024 and 2023, respectively. Realized gains and losses on energy derivatives for Level 3 recurring items are included in energy costs in the Company's consolidated statements of income under purchased electricity, electric generation fuel or purchased natural gas when settled. Unrealized gains and losses on energy derivatives for Level 3 recurring items are included in net unrealized (gain) loss on derivative instruments in the Company's consolidated statements of income. The Company does not use internally developed models to make adjustments to significant unobservable pricing inputs. The only significant unobservable input into the fair value measurement of the Company's Level 3 assets and liabilities is the forward price for electric and natural gas contracts. The weighted average price is calculated as the total market value divided by the total volume of the Company's Level 3 electric and natural gas commodity contracts, respectively, as of the reporting date. The following table presents the forward price ranges for the Company's Level 3 commodity contracts as of September 30, 2024: Puget Energy and Fair Value Range (Dollars in Thousands) Assets 1 Liabilities 1 Valuation Technique Unobservable Input Low High Weighted Average Electric $ 21,679 $ 110,149 Discounted cash flow Power prices (per MWh) $ 20.10 $ 149.85 $ 73.29 Natural gas $ 2,605 $ 665 Discounted cash flow Natural gas prices (per MMBtu) $ 2.10 $ 5.86 $ 4.50 _______________ 1 The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions. The following table presents the forward price ranges for the Company's Level 3 commodity contracts as of December 31, 2023: Puget Energy and Fair Value Range (Dollars in Thousands) Assets 1 Liabilities 1 Valuation Technique Unobservable Input Low High Weighted Average Electric $ 50,774 $ 23,512 Discounted cash flow Power prices (per MWh) $ 69.51 $ 188.63 $ 99.55 Natural gas $ 4,874 $ 1,023 Discounted cash flow Natural gas prices (per MMBtu) $ 2.20 $ 6.28 $ 3.55 _______________ 1 The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions. The significant unobservable inputs listed above would have a direct impact on the fair values of the above instruments if they were adjusted. Consequently, significant increases or decreases in the forward prices of electricity or natural gas in isolation would result in a significantly higher or lower fair value for Level 3 assets and liabilities. Generally, interrelationships exist between market prices of natural gas and power. As such, an increase in natural gas pricing would potentially have a similar impact on forward power markets. As of September 30, 2024 and December 31, 2023, a hypothetical 10% increase or decrease in market prices of natural gas and electricity would change the fair value of the Company's derivative portfolio, classified as Level 3 within the fair value hierarchy, by $60.1 million and $16.9 million, respectively. Long-Lived Assets Measured at Fair Value on a Nonrecurring Basis Puget Energy records the fair value of its intangible assets in accordance with ASC 360, “Property, Plant, and Equipment,” (ASC 360). The fair value assigned to the power contracts was determined using an income approach comparing the contract rate to the market rate for power over the remaining period of the contracts incorporating non-performance risk. Management also incorporated certain assumptions related to quantities and market presentation that it believes market participants would make in the valuation. The fair value of the power contracts is amortized as the contracts settle. ASC 360 requires long-lived assets to be tested for recoverability whenever events or changes in circumstances indicate that its carrying amount may not be recoverable. One such triggering event is a significant decrease in the forward market prices of power. As of September 30, 2024, Puget Energy completed valuation and impairment testing of its power purchase contracts classified as intangible assets and determined that no impairment was needed. These intangible assets exist as a result of the merger in 2009, at which time the consolidated assets and liabilities were revalued in accordance with ASC 805, "Business Combinations."

Retirement Benefits

Retirement Benefits	9 Months Ended
	Sep. 30, 2024
Subsidiaries [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Retirement Benefits PSE has a defined benefit pension plan (Qualified Pension Benefits) covering a substantial majority of PSE employees. For employees hired prior to 2014, pension benefits earned are a function of age, salary, years of service and, in the case of employees in the cash balance formula plan, the applicable annual interest crediting rates. Effective January 1, 2014, all new UA represented employees hired or rehired receive annual pay credits of 4.0% of eligible pay each year in the cash balance formula of the defined pension plan. Effective January 1, 2014 for non-represented employees, and December 12, 2014 for employees represented by the IBEW, newly hired or rehired employees receive annual employer contributions of 4.0% of eligible pay each year into the cash balance formula of the defined benefit pension or 401k plan account. PSE also has a non-qualified SERP for certain key senior management employees that closed to new participants in 2019. Effective 2019, PSE has an officer restoration benefit for new officers who join PSE or are promoted, such that company contributions under PSE’s applicable tax-qualified plan, which otherwise would have been credited if not for IRS limitations, are credited at 4.0% of earnings to an account with the Deferred Compensation Plan. In addition to providing pension benefits, PSE provides legacy group health care and life insurance benefits (Other Benefits) for certain retired employees. The group health care benefit is provided via a Retiree Health Reimbursement Account (HRA) Plan effective January 1, 2020. The life insurance benefits are provided principally through an insurance company. Puget Energy's retirement plans were remeasured as a result of the merger in 2009, which represents the difference between Puget Energy and PSE's retirement plans. The components of service cost are included within utility operations and maintenance for PSE and within non-utility expense and other for Puget Energy while all non-service cost components are included in other income. For further information, see Note 13, "Retirement Benefits" in the Combined Notes to Consolidated Financial Statements included in Item 8 of the Company's Form 10-K for the period ended December 31, 2023. The following tables summarize the Company’s net periodic benefit cost for the three and nine months ended September 30, 2024 and 2023: Puget Energy Qualified SERP Other Three Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 4,654 $ 4,632 $ — $ — $ 47 $ 44 Interest cost 7,788 8,094 342 370 97 99 Expected return on plan assets (13,724) (12,660) — — (61) (64) Amortization of prior service cost — — — — 8 7 Amortization of net loss (gain) (671) (612) (10) — (24) (57) Net periodic benefit cost $ (1,953) $ (546) $ 332 $ 370 $ 67 $ 29 Puget Energy Qualified SERP Other Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 13,962 $ 13,898 $ — $ 141 $ 148 $ 138 Interest cost 23,364 24,281 1,027 1,219 305 330 Expected return on plan assets (41,172) (37,980) — — (216) (223) Amortization of prior service cost — — — 146 25 21 Amortization of net loss (gain) (2,013) (1,836) (31) — (105) (158) Net periodic benefit cost $ (5,859) $ (1,637) $ 996 $ 1,506 $ 157 $ 108 Puget Sound Energy Qualified SERP Other Three Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 4,654 $ 4,632 $ — $ — $ 47 $ 44 Interest cost 7,788 8,094 342 370 97 99 Expected return on plan assets (13,724) (12,660) — — (61) (64) Amortization of prior service cost — — — — 8 7 Amortization of net loss (gain) — — (5) — (22) (64) Net periodic benefit cost $ (1,282) $ 66 $ 337 $ 370 $ 69 $ 22 Puget Sound Energy Qualified SERP Other Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 13,962 $ 13,898 $ — $ 141 $ 148 $ 138 Interest cost 23,364 24,281 1,027 1,219 305 330 Expected return on plan assets (41,172) (37,981) — — (216) (223) Amortization of prior service cost — — — 146 25 21 Amortization of net loss (gain) — — (16) 44 (105) (173) Net periodic benefit cost $ (3,846) $ 198 $ 1,011 $ 1,550 $ 157 $ 93 The following table summarizes the Company’s change in benefit obligation for the periods ended September 30, 2024 and December 31, 2023: Puget Energy and Qualified SERP Other Nine Months Ended Year Ended Nine Months Ended Year Ended Nine Months Ended Year Ended (Dollars in Thousands) September 30, December 31, September 30, December 31, September 30, December 31, Change in benefit obligation: Benefit obligation at beginning of period $ 609,103 $ 589,278 $ 26,824 $ 32,046 $ 8,597 $ 9,015 Amendments — — — — — 78 Service cost 13,962 18,530 — 143 148 184 Interest cost 23,364 32,375 1,027 1,589 305 439 Curtailment loss / (gain) — — — (2,772) — — Actuarial loss (gain) 1,450 8,469 — (661) 161 (52) Benefits paid (34,607) (38,258) (1,498) (3,521) (868) (1,067) Administrative expense — (1,291) — — — — Benefit obligation at end of period $ 613,272 $ 609,103 $ 26,353 $ 26,824 $ 8,343 $ 8,597

Regulation and Rates

Regulation and Rates	9 Months Ended
	Sep. 30, 2024
Entity Information [Line Items]
Regulation and Rates Disclosure	Regulation and Rates General Rate Case PSE filed a GRC which includes a two year MYRP with the Washington Commission on February 15, 2024, requesting an overall increase in electric and natural gas rates of 6.7% and 19.0% respectively in rate year one (expected to approximate calendar year 2025) and 8.5% and 2.1%, respectively in rate year two (expected to approximate calendar year 2026). PSE requested a return on equity of 9.95% for the first rate year beginning in 2025 and 10.5% for the second rate year beginning in 2026. PSE requested an overall rate of return of 7.65% in rate year one and 7.99% in rate year two. The filing requests recovery of forecasted plant additions through 2024 as required by Revised Code of Washington (RCW) 80.28.425 as well as forecasted plant additions through 2026, the final year of the MYRP. The procedural calendar for the adjudication of the case is set, with evidentiary hearing occurring on November 4th and 5th of 2024. The Company estimates the approved rates from this proceeding will become effective by statute approximately 11 months after filings. On August 6, 2024, intervenor response testimony was filed with the Washington Commission, to which PSE filed rebuttal testimony on September 18, 2024. On December 22, 2022, the Washington Commission issued an order on PSE’s 2022 GRC, which was filed on January 31, 2022 that approved a weighted cost of capital of 7.16%, or 6.62% after-tax, a capital structure of 49.0% in common equity in 2023 and 2024, and a return on equity of 9.4%. On January 6, 2023, the Washington Commission approved PSE’s natural gas rates in its compliance filing with an overall net revenue change of $70.8 million or 6.4% in 2023 and $19.5 million or 1.7% in 2024, with an effective date of January 7, 2023. On January 10, 2023, the Washington Commission approved PSE’s electric rates in its compliance filing with an overall net revenue change of $247.0 million or 10.8% in 2023 and $33.1 million or 1.3% in 2024 with an effective date of January 11, 2023. Per the 2022 GRC Final Order in Docket No. UE-220066, power cost only rate case (PCORC) rates were set to zero as of January 11, 2023 and PSE agreed not to file a PCORC during 2023 and 2024, the period covered by the two-year rate plan agreed to in the GRC settlement. Per the 2022 GRC Final Order in Docket No. UG-220067, PSE was authorized to seek recovery of the costs related to the Tacoma LNG Facility concurrent with its 2023 PGA filing. On April 24, 2024, the Washington Commission issued Final Order 07 under Docket No. UG-230393. The order determined that PSE acted prudently in developing and constructing the Tacoma LNG Facility after the initial decision to build in September 2016. Further, there were two main outcomes that resulted from the order. First, the Washington Commission did not authorize recovery of the portion of the Company’s deferred return on its investment in the Tacoma LNG Facility that was recorded between February 1, 2022, the date the facility was placed into service, and January 11, 2023, the date PSE’s 2022 GRC rates went into effect. Second, the Washington Commission directed PSE to increase the allocation of distribution pipeline investment to Puget LNG. The Washington Commission determined that the allocation should be tied to the relative flow of natural gas across these facilities, resulting in a higher allocation to Puget LNG than was originally filed. On May 3, 2024, PSE made the compliance filing required by Final Order 07. On May 24, 2024, Public Counsel and the Puyallup Tribe of Indians each filed a petition for judicial review of the Washington Commission’s Final Order 07. The petitions were filed in Thurston County Superior Court and are expected to be consolidated. Both petitions allege that the Washington Commission (i) failed to properly apply the updated public interest standard, (ii) failed to disallow all costs related to PSE’s redesign of the pipeline and development of waste gas disposal methods, and (iii) failed to conduct an independent determination of reasonable attorney fees. For further information, see Note 4, "Regulation and Rates" in the Combined Notes to Consolidated Financial Statements included in Item 8 of the Company's Form 10-K for the period ended December 31, 2023. Climate Commitment Act Deferral On December 29, 2022, PSE filed accounting petitions with the Washington Commission requesting authorization to defer costs and revenues associated with the Company’s compliance with the CCA codified in law within RCW 70A.65. On February 28, 2023, in Order 01 in Docket No. UE-220974 and UG-220975, the Washington Commission granted PSE approval to defer the cost of emission allowances to comply with the CCA and the proceeds from no-cost allowances consigned to auction beginning January 1, 2023. On August 3, 2023, the Washington Commission approved PSE's request for CCA rates in Docket No. UG-230470, subject to refund, effective October 1, 2023, to recover the estimated ongoing allowance costs and proportionate pass back of credits to customers from estimated auction proceeds during the period of August 2023 through December 2023. On October 26, 2023, the Washington Commission approved PSE's request for CCA rates in Docket No. UG-230756, subject to refund, effective November 1, 2023, to recover the estimated ongoing allowance costs and proportionate pass back of credit to customers from estimated auction proceeds during the period of January 2023 through September 2023. On November 22, 2023, PSE filed proposed revisions to its natural gas rates to incorporate allowance costs and auction proceeds in Docket UG-230968. In the filing PSE sought to update rates pertaining to amounts deferred from January 2023 through September 2023 and to add new language to the tariff that would enable PSE to fund decarbonization projects using a portion of the projected no cost allowances revenues. The request, as revised by PSE on December 19, 2023, represented a revenue increase of $29.1 million. The Washington Commission suspended the tariff sheets but allowed the rates to go into effect on an interim basis, subject to refund, on January 1, 2024. The Washington Commission had a hearing for the issue of risk sharing of CCA compliance costs on October 9, 2024 and has not yet issued an order. As of September 30, 2024, PSE has not sought cost recovery for its allowance costs for electric operations. The ongoing recovery of allowance costs and pass back of proceeds from the sale of consigned no-cost allowances for PSE's natural gas operations is consistent with the approved accounting petitions in Dockets No. UG-220975 and UG-230471. As of September 30, 2024, PSE recorded a regulatory liability of $89.9 million, which represents the amounts to date collected in customer natural gas rates for CCA obligation costs, net of the expense incurred for the purchase of allowances for electric and natural gas operations. Additionally, PSE will continue to consign for auction at least the minimum amount of no-cost emission allowances allocated for natural gas operations in compliance with the CCA, the proceeds of which will continue to be used for the benefit of natural gas customers, as determined by the Washington Commission. PSE does not record a regulatory liability to defer the proceeds until consigned allowances are sold at auction. As of September 30, 2024, PSE recorded a regulatory asset of $26.9 million, which represents the proceeds from the sale of consigned natural gas GHG emission allowances passed back through customer rates, net of proceeds received from the sale of consigned allowances sold at auction. Revenue Decoupling Adjustment Mechanism PSE performed an analysis to determine if electric and natural gas decoupling revenue deferrals would be collected from customers within 24 months of the annual period, per ASC 980. If not, for GAAP purposes only, PSE would need to record a reserve against the decoupling revenue and corresponding regulatory asset balance. Once the reserve is probable of collection within 24 months from the end of the annual period, the reserve can be recognized as decoupling revenue. Based on the analysis as of September 30, 2024, $0.1 million and zero reserve adjustment was recorded to electric and natural gas decoupling revenue as of September 30, 2024, respectively. No reserve adjustment was recorded for electric or natural gas decoupling revenue as of September 30, 2023. Power Cost Adjustment Mechanism PSE currently has a PCA mechanism that provides for the deferral of power costs that vary from the “power cost baseline” level of power costs. The “power cost baseline” levels are set, in part, based on normalized assumptions about weather and hydroelectric conditions. Excess power costs or savings are apportioned between PSE and its customers pursuant to the graduated scale set forth in the PCA mechanism and will trigger a surcharge or refund when the cumulative deferral trigger is reached. The following graduated scale is used in the PCA mechanism: Company’s Share Customers' Share Annual Power Cost Variability Over Under Over Under Over or under collected up to $17 million 100 % 100 % — % — % Over or under collected between $17 million - $40 million 35 50 65 50 Over or under collected beyond $40 million 10 10 90 90 For the nine months ended September 30, 2024, in its PCA mechanism, PSE under recovered its allowable costs by $111.1 million of which $75.5 million was apportioned to customers and $2.3 million of interest was accrued on the deferred customer balance. This compares to an over recovery of allowable costs of $66.2 million for the nine months ended September 30, 2023, of which $38.5 million was apportioned to customers and $3.6 million of interest was accrued on the total deferred customer balance. Power Cost Adjustment Clause PSE exceeded the $20.0 million cumulative deferral balance in its PCA mechanism in 2022. During 2022, actual power costs were higher than baseline power costs, thereby, creating an under-recovery of $110.1 million. Under the terms of the PCA’s sharing mechanism for under-recovered power costs, PSE absorbed $39.0 million of the under-recovered amount, and customers were responsible for the remaining $71.1 million, or $76.4 million including interest and adjusted for revenue sensitive items. On April 28, 2023, PSE filed the 2022 PCA report in Docket No. UE-230313 that proposed a recovery of the deferred balance, which included a revenue requirement increase of 0.9% in overall bill for all customers, with rates proposed to go into effect from December 1, 2023 through December 31, 2024. On September 29, 2023, PSE filed its variable power cost rates update as part of the 2022 GRC Order requirement in Docket No. UE-220066. The filing was approved in part on December 22, 2023, with updated rates effective January 1, 2024. PSE exceeded the $20.0 million cumulative deferral balance in its PCA mechanism in 2023. During 2023, actual power costs were lower than baseline power costs, thereby creating an over-recovery of $51.1 million. Under the terms of the PCA’s sharing mechanism for over-recovered costs, PSE’s share of the over-recovery was $26.2 million and customers were due the remaining $24.9 million, or $22.2 million including interest and adjusted for revenue sensitive items. On April 30, 2024, PSE filed the 2023 PCA compliance report, in Docket No. 240288, that proposed to pass back 2023 deferred balances from October 1, 2024 to December 31, 2025, resulting in credits to customers of $22.2 million. Additionally, PSE requested to recover the forecasted 2024 deferred balance of $98.2 million from October 1, 2024 to December 31, 2025. On September 26, 2024, the Washington Commission approved the filing as proposed with rates going into effect October 1, 2024 and January 1, 2025. Purchased Gas Adjustment Mechanism In October 2022, the Washington Commission approved PSE's request for PGA rates in Docket No. UG-220715, effective November 1, 2022. As part of that filing, PSE requested an annual revenue increase of $155.3 million, where PGA rates, under Schedule 101, increase annual revenue by $142.1 million, and the tracker rates under Schedule 106 increase annual revenue by $13.2 million. In November 2022, the FERC approved a settlement of a counterparty, FERC Docket No. RP17-346. Under the terms, PSE was allocated $24.2 million related to PSE natural gas services, which was recorded on December 31, 2022 and included below. The 2022 GRC order required PSE to amortize the refund in 2023 as a credit against natural gas costs and therefore pass back the refund to customers through the PGA mechanism. On October 26, 2023, the Washington Commission approved PSE's request for PGA rates in Docket No. UG-230769, effective November 1, 2023. As part of that filing, PSE requested an annual revenue decrease of $309.4 million, where PGA rates, under Schedule 101, decrease annual revenue by $93.9 million, and the tracker rates, under Schedule 106, decrease annual revenue by $215.5 million. The annual 2023 PGA rate decreases include the aforementioned counterparty settlement pass back of $28.1 million under Supplemental Schedule 106B. On October 24, 2024, the Washington Commission approved PSE's request for PGA rates in Docket No. UG-240708, effective November 1, 2024. As part of that filing, PSE requested an annual overall revenue increase of $124.4 million, where PGA rates, under Schedule 101, decrease annual revenue by $2.6 million and the tracker rates, under Schedule 106, increase annual revenue by $127.0 million. The revenue increase in Schedule 106 is primarily due to the cessation of the counterparty refund of $28.1 million, mentioned above, that was amortized as a credit in 2023 and $142.8 million in commodity deferrals that were passed back to customers. The following table presents the PGA mechanism balances and activity for the nine months ended September 30, 2024 and the twelve months ended December 31, 2023: Puget Energy and (Dollars in Thousands) At September 30, At December 31, 2024 2023 PGA (liability)/receivable beginning balance $ (132,082) $ (3,536) Actual natural gas costs 287,111 404,897 Allowed PGA recovery (210,102) (521,882) Interest (5,410) (7,639) Refund/interest from counterparty settlement — (3,922) PGA (liability)/receivable ending balance $ (60,483) $ (132,082) Storm Loss Deferral Mechanism

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	Commitments and Contingencies Legal Matters Washington Climate Commitment Act In 2021, the Washington Legislature adopted the CCA, which establishes a GHG emissions cap-and-invest program that requires covered entities, including electric and natural gas utilities, to purchase allowances to cover their GHG emissions with a cap on available allowances beginning on January 1, 2023 that declines annually through 2050. The WDOE published final regulations to implement the program on September 29, 2022, which became effective on October 30, 2022. The WDOE also indicated that there will be subsequent rulemakings building off initial rulemaking as program implementation proceeds and Washington carbon goal progress is evaluated. Compliance with the CCA requires covered entities to obtain allowances equal to their emissions and submit to the WDOE annually according to a staggered four-year compliance schedule. For the first three years of each compliance period, covered entities must submit allowances to cover at least 30% of their annual compliance obligation, as determined by the WDOE, no later than November 1st of the following year. For the fourth year of each compliance period, covered entities must submit sufficient allowances to cover 100% of their full four-year compliance obligation, as determined by the WDOE. The WDOE provided an initial allocation of no-cost allowances to electric utilities, including PSE, on April 24, 2023. However, qualifying electric utilities were allowed to submit revised emissions forecasts approved by the Washington Commission to WDOE. PSE filed its revised forecast of 2023 emission in Docket No. UE 220797, which was approved by the Washington Commission on July 27, 2023, and approved by the WDOE on September 27, 2023. Accordingly, the Company's compliance obligation as of September 30, 2024 reflects the revised allowance allocation in addition to allowances received based on PSE's forecast of 2023 and 2024 emissions. On September 30, 2024, the WDOE provided notice to PSE that its 2023 annual compliance obligation was confirmed based on its 2023 reported covered emissions as previously reported to the WDOE. On October 16, 2024, the WDOE held a meeting with electric utilities, including PSE, regarding CCA compliance issues related to calendar year 2023, at which time WDOE stated that based on current information it will not make further adjustments (or “true up”) accounting for allocation methods, forecasts or cost burden associated with calendar year 2023 for any electric utilities, including PSE, except for administrative costs, at the current time. The WDOE also indicated that there will be future meetings with electric utilities on how the adjustment (or “true-up”) mechanism will work going forward and that the WDOE would provide electric utilities advance notice if any such adjustments were being considered. Based on the determinations made by the WDOE in the aforementioned notices, PSE recorded a compliance obligation of $15.0 million for allowances for electric operations as of September 30, 2024. Given the potential for future rulemakings and the WDOE's ability to adjust no-cost allowances during the compliance period, there is estimation uncertainty surrounding the Company's ability to estimate its compliance obligation both on an annual basis and a four-year compliance period, prior to a final WDOE determination. As existing uncertainties are resolved in future periods, any change in compliance costs as a result of such estimated additional liabilities would be deferred under ASC 980 as a regulatory asset consistent with Docket No. UE-220974, as these amounts will be recoverable from customers in future utility rates. As a result, there is no current impact to the Company's consolidated statements of income. Colstrip PSE has a 50% ownership interest in Colstrip Units 1 and 2 and a 25% interest in each of Colstrip Units 3 and 4, which are coal-fired generating units located in Colstrip, Montana. PSE has accelerated the depreciation of Colstrip Units 3 and 4 to December 31, 2025 as part of the 2019 GRC. The 2017 GRC repurposed PTCs and hydro-related treasury grants to recover unrecovered plant costs and to fund and recover decommissioning and remediation costs for Colstrip Units 1 through 4. Additional costs beyond those covered by PTCs and hydro-related treasury grants are being recovered through a separate Colstrip tariff as part of the 2022 GRC. In 2022, PSE and Talen Energy signed an agreement to transfer PSE's ownership interest in Colstrip Units 3 and 4 to Talen Energy on December 31, 2025. However, Talen emerged from a Chapter 11 bankruptcy in May 2023 without approval of the 2022 transfer agreement, which the parties agree makes the transfer agreement unenforceable. Given that the transfer contemplated by that agreement will not proceed, PSE entered into an agreement with NorthWestern Energy on July 30, 2024 to transfer PSE's ownership interest in Colstrip Units 3 and 4 to NorthWestern Energy on December 31, 2025. Management evaluated Colstrip Units 3 and 4 and determined that the applicable held for sale and abandonment accounting criteria were not met as of December 31, 2023 and September 30, 2024. Colstrip Units 3 and 4 are classified as electric utility plant on the Company's balance sheet as of September 30, 2024 and December 31, 2023. Other Commitments and Contingencies In addition to the contractual obligations and consolidated commercial commitments disclosed in the Company's Annual Report on Form 10-K for the year ended December 31, 2023, during the nine months ended September 30, 2024, the Company entered into new Electric Portfolio and Electric Wholesale Market Transaction contracts with estimated payment obligations totaling $2.7 billion through 2053. For further information, see Part II, Item 8, Note 16, "Commitments and Contingencies" in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023.

Leases (Notes)

Leases (Notes)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Leases	Leases As of September 30, 2024, there have been no material changes regarding the Company's leases. For further information, see Part II, Item 8, Note 9, "Leases" in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Leases Not Yet Commenced On September 20, 2023, PSE entered into a tolling agreement to purchase the energy and capacity associated with a 132.5 MW facility. The tolling agreement represents a lease to PSE, and is expected to commence in October 2025. PSE expects the future minimum lease payments to be $91.0 million over the five year period beginning in October 2025. On December 12, 2023, PSE entered into a lease for an operations training facility located in Puyallup, Washington. The lease is expected to commence in 2025 and PSE expects the future minimum lease payments to be $116.0 million over the 20 years term. Construction of the facility will be managed and contracted by the lessor, however, PSE will have involvement in the design of the facility. On May 8, 2024, PSE entered into a battery storage tolling agreement that will be accounted for as a lease upon commencement. The lease is expected to commence in August 2027 and has a term of 20 years. The expected total contract consideration will approximate $744.0 million over the lease term. On May 23, 2024, PSE entered into a battery storage tolling agreement that will be accounted for as a lease upon commencement. The lease is expected to commence in September 2027 and has a term of 25 years. The expected total contract consideration will approximate $856.2 million over the lease term.
Leases	Leases As of September 30, 2024, there have been no material changes regarding the Company's leases. For further information, see Part II, Item 8, Note 9, "Leases" in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Leases Not Yet Commenced On September 20, 2023, PSE entered into a tolling agreement to purchase the energy and capacity associated with a 132.5 MW facility. The tolling agreement represents a lease to PSE, and is expected to commence in October 2025. PSE expects the future minimum lease payments to be $91.0 million over the five year period beginning in October 2025. On December 12, 2023, PSE entered into a lease for an operations training facility located in Puyallup, Washington. The lease is expected to commence in 2025 and PSE expects the future minimum lease payments to be $116.0 million over the 20 years term. Construction of the facility will be managed and contracted by the lessor, however, PSE will have involvement in the design of the facility. On May 8, 2024, PSE entered into a battery storage tolling agreement that will be accounted for as a lease upon commencement. The lease is expected to commence in August 2027 and has a term of 20 years. The expected total contract consideration will approximate $744.0 million over the lease term. On May 23, 2024, PSE entered into a battery storage tolling agreement that will be accounted for as a lease upon commencement. The lease is expected to commence in September 2027 and has a term of 25 years. The expected total contract consideration will approximate $856.2 million over the lease term.

Other

Other	9 Months Ended
	Sep. 30, 2024
Other [Abstract]
Debt Disclosure	Other Long-Term Debt On June 11, 2024, PSE issued $400.0 million of senior secured notes at an interest rate of 5.330%. The notes mature on June 15, 2034 and pay interest semi-annually in arrears on June 15 and December 15 of each year, commencing on December 15, 2024. Proceeds from the issuance of the notes were invested in short-term money market funds, used to pay down outstanding commercial paper and for general corporate purposes. On June 11, 2024, PSE issued $400.0 million of green senior secured notes at an interest rate of 5.685%. The notes mature on June 15, 2054 and pay interest semi-annually in arrears on June 15 and December 15 of each year, commencing on December 15, 2024. Net proceeds from the issuance of the notes were invested in short-term money market funds and are intended to be used for allocation to eligible projects, as defined in PSE’s sustainable financing framework, which was published in May 2023. Eligible Projects are expenditures incurred and investments made related to development and acquisition of some or all of the following types of projects: (i) renewable energy, (ii) energy efficiency, (iii) clean transportation, (iv) biodiversity conservation, (v) climate change adaptation, (vi) water and wastewater management, (vii) pollution prevention and control, and (viii) green innovation. Liquidity Facilities and Other Financing Arrangements As of September 30, 2024, $371.1 million was drawn and outstanding under Puget Energy's facility, which was classified as short-term debt on Puget Energy's consolidated balance sheet. As of September 30, 2024, there was no amount outstanding under the commercial paper program at PSE and no amount was drawn under PSE's credit facility. Outside of the credit facility, PSE maintains a standby letter of credit with TD Bank allowing for standby letter of credit postings of up to $150.0 million as a condition of transacting on the ICE NGX platform as well as participating in the Washington state carbon allowance auctions. As of September 30, 2024, $4.1 million was issued under a standby letter of credit with TD Bank in support of natural gas purchases on the NGX in Canada. Additionally, PSE had a $1.9 million letter of credit in support of a long-term transmission contract. In support of purchase power contracts, PSE posted cash collateral of $15.2 million and maintained two standby letters of credit in the amounts of $24.0 million and $13.5 million. On June 17, 2024, Puget Energy received $292.8 million as an equity contribution from Puget Equico LLC, Puget Energy's parent company. Puget Energy then contributed $292.8 million to PSE as an equity contribution. The proceeds from the equity contribution were used for general corporate purposes. For further information on the Company's long-term and short-term debt, credit facilities and other financing arrangements, see Part II, Item 8, Note 7, "Long-Term Debt" and Note 8, "Liquidity Facilities and Other Financing Arrangements" in the Company's Annual Report on Form 10-K for the year ended December 31, 2023. Beaver Creek Wind Project Beaver Creek is a utility-scale wind project located in Stillwater County, Montana, with an expected nameplate capacity of 248 MW that is expected to commence commercial operations in 2025. On September 15, 2023, PSE executed a membership interest purchase agreement with Caithness Beaver Creek, LLC for a 100% ownership interest in Caithness Montana Wind, LLC, which closed on December 1, 2023. Total consideration is expected to be $44.6 million of which $23.8 million has been paid as of September 30, 2024 and the remaining balance is expected to be paid in the third quarter of 2025. On December 1, 2023, PSE entered into a turbine supply agreement with GE Renewables North America, LLC to purchase 88 wind turbines. Total consideration is expected to be $266.9 million of which $229.5 million has been paid as of September 30, 2024 and the remaining balance is expected to paid throughout 2024 and the first quarter of 2025 as turbines are delivered and the project is completed. On January 26, 2024, PSE entered into a balance of plant agreement to complete the design and construction of the project. Total consideration is expected to be approximately $145.4 million. As of September 30, 2024, $461.5 million and $19.2 million was recorded to construction work in progress and ARO, respectively, in conjunction with the Beaver Creek wind project. Appaloosa Solar Project

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Parent	$ (121,108)	$ (29,076)	$ 129,909	$ (5,297)	$ (36,910)	$ (31)	$ (20,275)	$ (42,238)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Consolidation and _2

Summary of Consolidation and Significant Accounting Policy (Tables)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Accounts Receivable, Allowance for Credit Loss	The following table presents the activity in the allowance for credit losses for accounts receivable for the nine months ended September 30, 2024 and 2023: Puget Energy and Nine Months (Dollars in Thousands) 2024 2023 Allowance for credit losses: Beginning balance $ 38,211 $ 41,962 Provision for credit loss expense 26,570 23,550 Receivables charged-off (30,783) (29,005) Total ending allowance balance 1 $ 33,998 $ 36,507 _____________ 1 $23.6 million and $12.2 million of provision related to balances of deferred costs specific to COVID-19 as of September 30, 2024 and 2023, respectively.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables present disaggregated revenue from contracts with customers, and other revenue by major source for the three and nine months ended September 30, 2024 and September 30, 2023: Puget Energy and Puget Sound Energy (Dollars in Thousands) Three Months Ended September 30, 2024 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 346,658 $ 78,517 $ — $ 425,175 Commercial 281,178 49,614 — 330,792 Industrial 31,634 3,818 — 35,452 Other 5,795 — — 5,795 Wholesale 68,485 — — 68,485 Transmission and transportation 7,297 6,434 — 13,731 Miscellaneous 2 11,250 41,464 8,694 61,408 Total revenue from contracts with customers $ 752,297 $ 179,847 $ 8,694 $ 940,838 Total other revenue 3 (16,184) 2,890 — (13,294) Total operating revenue $ 736,113 $ 182,737 $ 8,694 $ 927,544 _____________ 1 Other includes $8.7 million of Puget LNG revenues recorded at Puget Energy. 2 Miscellaneous natural gas revenue includes $41.2 million for the regulatory offset of CCA auction proceeds passed back to customers. 3 Puget Energy and (Dollars in Thousands) Three Months Ended September 30, 2023 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 292,586 $ 91,393 $ — $ 383,979 Commercial 252,952 51,132 — 304,084 Industrial 29,794 4,003 — 33,797 Other 5,242 — — 5,242 Wholesale 174,039 — — 174,039 Transmission and transportation 10,403 4,540 — 14,943 Miscellaneous 7,895 (1,273) 10,381 17,003 Total revenue from contracts with customers $ 772,911 $ 149,795 $ 10,381 $ 933,087 Total other revenue 2 (2,505) 10,438 — 7,933 Total operating revenue $ 770,406 $ 160,233 $ 10,381 $ 941,020 _____________ 1 Other includes $9.4 million of Puget LNG revenues recorded at Puget Energy. 2 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Puget Energy and (Dollars in Thousands) Nine Months Ended September 30, 2024 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 1,207,130 $ 522,522 $ — $ 1,729,652 Commercial 857,267 250,068 — 1,107,335 Industrial 97,750 18,685 — 116,435 Other 17,585 — — 17,585 Wholesale 223,596 — — 223,596 Transmission and transportation 26,619 22,144 — 48,763 Miscellaneous 2 23,463 200,768 24,375 248,606 Total revenue from contracts with customers $ 2,453,410 $ 1,014,187 $ 24,375 $ 3,491,972 Total other revenue 3 (18,952) 2,909 — (16,043) Total operating revenue $ 2,434,458 $ 1,017,096 $ 24,375 $ 3,475,929 _____________ 1 Other includes $24.2 million of Puget LNG revenues recorded at Puget Energy. 2 Miscellaneous natural gas revenue includes $206.0 million for the regulatory offset of CCA auction proceeds passed back to customers. 3 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Puget Energy and (Dollars in Thousands) Nine Months Ended September 30, 2023 Revenue from contracts with customers: Electric Natural Gas Other 1 Total Retail Residential $ 1,089,794 $ 612,458 $ — $ 1,702,252 Commercial 792,644 285,194 — 1,077,838 Industrial 92,161 21,286 — 113,447 Other 15,963 — — 15,963 Wholesale 376,191 — — 376,191 Transmission and transportation 35,516 15,493 — 51,009 Miscellaneous 18,870 (1,691) 36,999 54,178 Total revenue from contracts with customers $ 2,421,139 $ 932,740 $ 36,999 $ 3,390,878 Total other revenue 2 40,066 14,891 — 54,957 Total operating revenue $ 2,461,205 $ 947,631 $ 36,999 $ 3,445,835 _____________ 1 Other includes $20.7 million of Puget LNG revenues recorded at Puget Energy. 2 Total other revenue includes revenues from derivatives and alternative revenue programs that are not considered revenues from contracts with customers.
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Based on management’s best estimate of commencement, the Company expects to recognize this revenue over the following time periods: Puget Energy (Dollars in Thousands) 2024 2025 2026 2027 2028 Thereafter Total Remaining performance obligations $ 5,238 $ 19,828 $ 19,454 $ 19,454 $ 19,454 $ 102,135 $ 185,563

Accounting for Derivative Ins_2

Accounting for Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2024
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the volumes, fair values and classification of the Company's derivative instruments recorded on the balance sheets: Puget Energy and September 30, 2024 December 31, 2023 (Dollars in Thousands) Volumes (millions) Assets 1 Liabilities 2 Volumes (millions) Assets 1 Liabilities 2 Electric portfolio derivatives * $ 39,585 $ 205,209 * $ 93,028 $ 126,939 Natural gas derivatives (MMBtus) 3 237 5,909 55,720 301 16,521 96,898 Total derivative contracts $ 45,494 $ 260,929 $ 109,549 $ 223,837 Current $ 31,373 $ 147,866 $ 74,225 $ 185,788 Long-term 14,121 113,063 35,324 38,049 Total derivative contracts $ 45,494 $ 260,929 $ 109,549 $ 223,837 _______________ 1 Balance sheet classification: Current and Long-term Unrealized gain on derivative instruments. 2 Balance sheet classification: Current and Long-term Unrealized loss on derivative instruments. 3 All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, “Regulated Operations,” due to the PGA mechanism. The net derivative asset or liability and offsetting regulatory liability or asset are related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. * Electric portfolio derivatives consist of electric generation fuel of 254.9 million MMBtu and purchased electricity of 13.4 million MWhs at September 30, 2024, and 315.6 million MMBtus and 2.3 million MWhs at December 31, 2023.
Offsetting Assets and Liabilities	The following tables present the potential effect of netting arrangements, including rights of set-off associated with the Company's derivative assets and liabilities: Puget Energy and At September 30, 2024 Gross Amount Recognized in the Statement of Financial Position 1 Gross Amounts Offset in the Statement of Financial Position Net of Amounts Presented in the Statement of Financial Position Gross Amounts Not Offset in the Statement of Financial Position (Dollars in Thousands) Commodity Contracts Cash Collateral Received/Posted Net Amount Assets: Energy derivative contracts $ 45,494 $ — $ 45,494 $ (39,821) $ — $ 5,673 Liabilities: Energy derivative contracts $ 260,929 $ — $ 260,929 $ (39,821) $ (6,030) $ 215,078 Puget Energy and At December 31, 2023 Gross Amount Recognized in the Statement of Financial Position 1 Gross Amounts Offset in the Statement of Financial Position Net of Amounts Presented in the Statement of Financial Position Gross Amounts Not Offset in the Statement of Financial Position (Dollars in Thousands) Commodity Contracts Cash Collateral Received/Posted Net Amount Assets: Energy derivative contracts $ 109,549 $ — $ 109,549 $ (82,206) $ — $ 27,343 Liabilities: Energy derivative contracts $ 223,837 $ — $ 223,837 $ (82,206) $ (84) $ 141,547 _______________ 1
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table presents the effect and classification of the realized and unrealized gains (losses) of the Company's derivatives recorded on the statements of income: Puget Energy and Three Months Ended Nine Months Ended (Dollars in Thousands) Classification 2024 2023 2024 2023 Gas for power derivatives: Unrealized Unrealized gain (loss) on derivative instruments, net $ (6,807) $ 38,966 $ (3,550) $ (75,373) Realized Electric generation fuel (32,988) (23,442) (63,888) 51,253 Power derivatives: Unrealized Unrealized gain (loss) on derivative instruments, net (102,172) (17,271) (128,162) (125,857) Realized Purchased electricity (14,977) 25,076 (61,307) 72,208 Total gain (loss) recognized in income on derivatives $ (156,944) $ 23,329 $ (256,907) $ (77,769)
Schedule of Credit Risk Related Contingent Features	The following table presents the aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a liability position and the amount of additional collateral the Company could be required to post: Puget Energy and (Dollars in Thousands) At September 30, 2024 At December 31, 2023 Fair Value 1 Posted Contingent Fair Value 1 Posted Contingent Contingent Feature Liability Collateral Collateral Liability Collateral Collateral Credit rating 2 $ 112,218 $ — $ 112,218 $ 13,384 $ — $ 13,384 Requested credit for adequate assurance 31,565 — — 53,427 — — Forward value of contract 3 6,412 9,742 N/A 84 12,429 N/A Total $ 150,195 $ 9,742 $ 112,218 $ 66,895 $ 12,429 $ 13,384 _______________ 1 Represents the derivative fair value of contracts with contingent features for counterparties in net derivative liability positions. Excludes NPNS, accounts payable and accounts receivable. 2 Failure by PSE to maintain an investment grade credit rating from each of the major credit rating agencies provides counterparties a contractual right to demand collateral. 3 Collateral requirements may vary based on changes in the forward value of underlying transactions relative to contractually defined collateral thresholds.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Inputs, Liabilities, Quantitative Information	The fair value of the long-term notes was estimated using the discounted cash flow method with the U.S. Treasury yields and the Company's credit spreads as inputs, interpolating to the maturity date of each issue. The carrying values and estimated fair values were as follows: Puget Energy September 30, 2024 December 31, 2023 (Dollars in Thousands) Level Carrying Fair Carrying Fair Liabilities: Long-term debt (fixed-rate), net of discount 1 2 $ 7,437,695 $ 7,396,449 $ 7,036,642 $ 6,855,503 Total liabilities $ 7,437,695 $ 7,396,449 $ 7,036,642 $ 6,855,503 Puget Sound Energy September 30, 2024 December 31, 2023 (Dollars in Thousands) Level Carrying Fair Carrying Fair Liabilities: Long-term debt (fixed-rate), net of discount 2 2 $ 5,977,376 $ 5,869,739 $ 5,184,047 $ 5,007,483 Total liabilities $ 5,977,376 $ 5,869,739 $ 5,184,047 $ 5,007,483 _______________ 1 The carrying value includes debt issuances costs of $21.8 million and $21.0 million for September 30, 2024 and December 31, 2023, respectively, which are not included in fair value. 2 The carrying value includes debt issuances costs of $22.5 million and $21.2 million for September 30, 2024 and December 31, 2023, respectively, which are not included in fair value.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents the Company's financial assets and liabilities by level, within the fair value hierarchy, that were accounted for at fair value on a recurring basis: Puget Energy and Fair Value Fair Value (Dollars in Thousands) Level 2 Level 3 Total Level 2 Level 3 Total Assets: Electric derivative instruments $ 17,906 $ 21,679 $ 39,585 $ 42,254 $ 50,774 $ 93,028 Natural gas derivative instruments 3,304 2,605 5,909 11,647 4,874 16,521 Total assets $ 21,210 $ 24,284 $ 45,494 $ 53,901 $ 55,648 $ 109,549 Liabilities: Electric derivative instruments $ 95,060 $ 110,149 $ 205,209 $ 103,427 $ 23,512 $ 126,939 Natural gas derivative instruments 55,055 665 55,720 95,875 1,023 96,898 Compliance obligations 70,431 — 70,431 168,879 — 168,879 Total liabilities $ 220,546 $ 110,814 $ 331,360 $ 368,181 $ 24,535 $ 392,716 The following tables presents the Company's reconciliation of the changes in the fair value of Level 3 derivatives in the fair value hierarchy:
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	Puget Energy and Three Months Ended September 30, (Dollars in Thousands) 2024 2023 Level 3 Roll-Forward Net Asset/(Liability) Electric Natural Gas Total Electric Natural Gas Total Balance at beginning of period $ 3,041 $ 2,022 $ 5,063 $ 57,907 $ 104 $ 58,011 Changes during period: Realized and unrealized energy derivatives: Included in earnings 1 (97,624) — (97,624) (12,551) — (12,551) Included in regulatory assets / liabilities — 1,217 1,217 — 3,808 3,808 Settlements 6,113 (1,299) 4,814 (9,752) (351) (10,103) Transferred into Level 3 — — — — — — Transferred out of Level 3 — — — — — — Balance at end of period $ (88,470) $ 1,940 $ (86,530) $ 35,604 $ 3,561 $ 39,165 Puget Energy and Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 Level 3 Roll-Forward Net Asset/(Liability) Electric Natural Gas Total Electric Natural Gas Total Balance at beginning of period $ 27,262 $ 3,851 $ 31,113 $ 116,078 $ (127) $ 115,951 Changes during period: Realized and unrealized energy derivatives: Included in earnings 2 (148,522) — (148,522) (47,613) — (47,613) Included in regulatory assets / liabilities — 1,741 1,741 — 3,852 3,852 Settlements 32,790 (3,652) 29,138 (33,078) (334) (33,412) Transferred into Level 3 — — — — — — Transferred out of Level 3 — — — 217 170 387 Balance at end of period $ (88,470) $ 1,940 $ (86,530) $ 35,604 $ 3,561 $ 39,165 _______________ 1 Income Statement locations: Unrealized gain (loss) on derivative instruments, net. Amounts include unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(90.9) million and $(16.1) million for the three months ended September 30, 2024 and 2023, respectively. 2 Income Statement locations: Unrealized gain (loss) on derivative instruments, net. Amounts include unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(112.4) million and $(25.9) million for the nine months ended September 30, 2024 and 2023, respectively.
Fair Value Inputs, Assets and Liabilities, Quantitative Information	The following table presents the forward price ranges for the Company's Level 3 commodity contracts as of September 30, 2024: Puget Energy and Fair Value Range (Dollars in Thousands) Assets 1 Liabilities 1 Valuation Technique Unobservable Input Low High Weighted Average Electric $ 21,679 $ 110,149 Discounted cash flow Power prices (per MWh) $ 20.10 $ 149.85 $ 73.29 Natural gas $ 2,605 $ 665 Discounted cash flow Natural gas prices (per MMBtu) $ 2.10 $ 5.86 $ 4.50 _______________ 1 The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions. The following table presents the forward price ranges for the Company's Level 3 commodity contracts as of December 31, 2023: Puget Energy and Fair Value Range (Dollars in Thousands) Assets 1 Liabilities 1 Valuation Technique Unobservable Input Low High Weighted Average Electric $ 50,774 $ 23,512 Discounted cash flow Power prices (per MWh) $ 69.51 $ 188.63 $ 99.55 Natural gas $ 4,874 $ 1,023 Discounted cash flow Natural gas prices (per MMBtu) $ 2.20 $ 6.28 $ 3.55 _______________ 1 The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions.

Retirement Benefits (Tables)

Retirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2024
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs	The following tables summarize the Company’s net periodic benefit cost for the three and nine months ended September 30, 2024 and 2023: Puget Energy Qualified SERP Other Three Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 4,654 $ 4,632 $ — $ — $ 47 $ 44 Interest cost 7,788 8,094 342 370 97 99 Expected return on plan assets (13,724) (12,660) — — (61) (64) Amortization of prior service cost — — — — 8 7 Amortization of net loss (gain) (671) (612) (10) — (24) (57) Net periodic benefit cost $ (1,953) $ (546) $ 332 $ 370 $ 67 $ 29 Puget Energy Qualified SERP Other Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 13,962 $ 13,898 $ — $ 141 $ 148 $ 138 Interest cost 23,364 24,281 1,027 1,219 305 330 Expected return on plan assets (41,172) (37,980) — — (216) (223) Amortization of prior service cost — — — 146 25 21 Amortization of net loss (gain) (2,013) (1,836) (31) — (105) (158) Net periodic benefit cost $ (5,859) $ (1,637) $ 996 $ 1,506 $ 157 $ 108 Puget Sound Energy Qualified SERP Other Three Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 4,654 $ 4,632 $ — $ — $ 47 $ 44 Interest cost 7,788 8,094 342 370 97 99 Expected return on plan assets (13,724) (12,660) — — (61) (64) Amortization of prior service cost — — — — 8 7 Amortization of net loss (gain) — — (5) — (22) (64) Net periodic benefit cost $ (1,282) $ 66 $ 337 $ 370 $ 69 $ 22 Puget Sound Energy Qualified SERP Other Nine Months Ended September 30, (Dollars in Thousands) 2024 2023 2024 2023 2024 2023 Components of net periodic benefit cost: Service cost $ 13,962 $ 13,898 $ — $ 141 $ 148 $ 138 Interest cost 23,364 24,281 1,027 1,219 305 330 Expected return on plan assets (41,172) (37,981) — — (216) (223) Amortization of prior service cost — — — 146 25 21 Amortization of net loss (gain) — — (16) 44 (105) (173) Net periodic benefit cost $ (3,846) $ 198 $ 1,011 $ 1,550 $ 157 $ 93
Schedule of Changes in Projected Benefit Obligations	The following table summarizes the Company’s change in benefit obligation for the periods ended September 30, 2024 and December 31, 2023: Puget Energy and Qualified SERP Other Nine Months Ended Year Ended Nine Months Ended Year Ended Nine Months Ended Year Ended (Dollars in Thousands) September 30, December 31, September 30, December 31, September 30, December 31, Change in benefit obligation: Benefit obligation at beginning of period $ 609,103 $ 589,278 $ 26,824 $ 32,046 $ 8,597 $ 9,015 Amendments — — — — — 78 Service cost 13,962 18,530 — 143 148 184 Interest cost 23,364 32,375 1,027 1,589 305 439 Curtailment loss / (gain) — — — (2,772) — — Actuarial loss (gain) 1,450 8,469 — (661) 161 (52) Benefits paid (34,607) (38,258) (1,498) (3,521) (868) (1,067) Administrative expense — (1,291) — — — — Benefit obligation at end of period $ 613,272 $ 609,103 $ 26,353 $ 26,824 $ 8,343 $ 8,597

Regulation and Rates (Tables)

Regulation and Rates (Tables) - Subsidiaries [Member]	9 Months Ended
	Sep. 30, 2024
Purchased Gas Adjustment [Member] | Natural Gas
Regulation and Rates [Line Items]
Schedule of PGA Receivable Payable	The following table presents the PGA mechanism balances and activity for the nine months ended September 30, 2024 and the twelve months ended December 31, 2023: Puget Energy and (Dollars in Thousands) At September 30, At December 31, 2024 2023 PGA (liability)/receivable beginning balance $ (132,082) $ (3,536) Actual natural gas costs 287,111 404,897 Allowed PGA recovery (210,102) (521,882) Interest (5,410) (7,639) Refund/interest from counterparty settlement — (3,922) PGA (liability)/receivable ending balance $ (60,483) $ (132,082)
PCA Mechanism [Member] | Electricity
Regulation and Rates [Line Items]
Schedule of Graduated Scale of Rate Adjustment Mechanism	The following graduated scale is used in the PCA mechanism: Company’s Share Customers' Share Annual Power Cost Variability Over Under Over Under Over or under collected up to $17 million 100 % 100 % — % — % Over or under collected between $17 million - $40 million 35 50 65 50 Over or under collected beyond $40 million 10 10 90 90

Summary of Consolidation and _3

Summary of Consolidation and Significant Accounting Policy - Narrative (Details) $ in Millions	1 Months Ended			9 Months Ended
	Feb. 28, 2021	May 31, 2020	Apr. 30, 2017	Sep. 30, 2024 USD ($) mi²	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Puget LNG [Member]
Summary of Consolidation Policy
Operating Costs and Expenses				$ 17.4	$ 20.3
Subsidiaries [Member]
Summary of Consolidation Policy
Area of Service Territory (in sqmi) | mi²				6,000
Variable Interest Entity, Measure of Activity, Expense				$ 65.7	$ 64.2
Variable Interest Entity, Payable				11.7		$ 14.6
Subsidiaries [Member] | Skookumchuck Wind Energy Project
Summary of Consolidation Policy
Contract Length, PPA			20 years
Subsidiaries [Member] | Golden Hills Wind Farm
Summary of Consolidation Policy
Contract Length, PPA		20 years
Subsidiaries [Member] | Clearwater Wind Project
Summary of Consolidation Policy
Contract Length, PPA	25 years
Subsidiaries [Member] | Natural Gas | Tacoma LNG [Member]
Summary of Consolidation Policy
Construction in Progress, Gross				$ 230.5		235.6
Subsidiaries [Member] | Tacoma LNG [Member]
Summary of Consolidation Policy
Jointly Owned Non-Utility Plant Share				43%
Puget LNG [Member]
Summary of Consolidation Policy
Jointly Owned Non-Utility Plant Share				57%
Puget LNG [Member] | Natural Gas | Tacoma LNG [Member]
Summary of Consolidation Policy
Construction in Progress, Gross				$ 236.1		$ 240.5
Variable Interest Entity, Not Primary Beneficiary
Summary of Consolidation Policy
Equity Method Investments				$ 0

Summary of Consolidation and _4

Summary of Consolidation and Significant Accounting Policy - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 38,211	$ 41,962
Provision for credit loss expense	26,570	23,550
Receivables charged-off	(30,783)	(29,005)
Total ending allowance balance1	33,998	36,507
Bad Debt Deferral, COVID 19	$ 23,600	$ 12,200

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 940,838	$ 933,087	$ 3,491,972	$ 3,390,878
Total other revenue3	(13,294)	7,933	(16,043)	54,957
Electric	736,113	770,406	2,434,458	2,461,205
Natural gas	182,737	160,233	1,017,096	947,631
Other	8,694	10,381	24,375	36,999
Revenues	927,544	941,020	3,475,929	3,445,835
Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	752,297	772,911	2,453,410	2,421,139
Total other revenue3	(16,184)	(2,505)	(18,952)	40,066
Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	179,847	149,795	1,014,187	932,740
Total other revenue3	2,890	10,438	2,909	14,891
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	8,694	10,381	24,375	36,999
Total other revenue3	0	0	0	0
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	425,175	383,979	1,729,652	1,702,252
Residential | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	346,658	292,586	1,207,130	1,089,794
Residential | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	78,517	91,393	522,522	612,458
Residential | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	330,792	304,084	1,107,335	1,077,838
Commercial | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	281,178	252,952	857,267	792,644
Commercial | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	49,614	51,132	250,068	285,194
Commercial | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	35,452	33,797	116,435	113,447
Industrial | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	31,634	29,794	97,750	92,161
Industrial | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,818	4,003	18,685	21,286
Industrial | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Other Retail Customer
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,795	5,242	17,585	15,963
Other Retail Customer | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,795	5,242	17,585	15,963
Other Retail Customer | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Other Retail Customer | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Wholesale
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68,485	174,039	223,596	376,191
Wholesale | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68,485	174,039	223,596	376,191
Wholesale | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Wholesale | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Transmission and Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	13,731	14,943	48,763	51,009
Transmission and Transportation | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7,297	10,403	26,619	35,516
Transmission and Transportation | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6,434	4,540	22,144	15,493
Transmission and Transportation | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
Miscellaneous Customer
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	61,408	17,003	248,606	54,178
Miscellaneous Customer | Electric
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11,250	7,895	23,463	18,870
Miscellaneous Customer | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	41,464	(1,273)	200,768	(1,691)
Miscellaneous Customer | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	8,694	10,381	24,375	36,999
Miscellaneous Customer | Other | Puget LNG [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 8,700	$ 9,400	$ 24,200	$ 20,700

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		$ 940,838	$ 933,087	$ 3,491,972	$ 3,390,878
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		8,694	10,381	24,375	36,999
Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		179,847	149,795	1,014,187	932,740
Miscellaneous Customer
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		61,408	17,003	248,606	54,178
Miscellaneous Customer | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		8,694	10,381	24,375	36,999
Miscellaneous Customer | Natural Gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		41,464	(1,273)	200,768	(1,691)
Puget LNG [Member]
Disaggregation of Revenue [Line Items]
Remaining Contract Term, PLNG	10 years
Puget LNG [Member] | Miscellaneous Customer | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers		8,700	$ 9,400	24,200	$ 20,700
Subsidiaries [Member] | Natural Gas
Disaggregation of Revenue [Line Items]
Deferred Emission Compliance Auction Proceeds, Passback to Customers		$ 41,200		$ 206,000

Revenue - Performance Obligatio

Revenue - Performance Obligations (Details) - Puget LNG [Member] $ in Thousands	Sep. 30, 2024 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 185,563
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 5,238
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 19,828
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 19,454
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 19,454
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 19,454
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 102,135
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period

Accounting for Derivative Ins_3

Accounting for Derivative Instruments and Hedging Activities - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Subsidiaries [Member]
Derivative [Line Items]
Hedging strategy number of years extended	3 years
Natural Gas Portfolio [Member]
Derivative [Line Items]
Posted Collateral	$ 0
External Credit Rating, Investment Grade [Member]
Derivative [Line Items]
Derivative, Credit Risk Exposure, Percentage	99.80%
External Credit Rating, Non Investment Grade [Member]
Derivative [Line Items]
Derivative, Credit Risk Exposure, Percentage	0.20%

Accounting for Derivative Ins_4

Accounting for Derivative Instruments and Hedging Activities - Derivative Assets and Liabilities (Details) $ in Thousands, MMBTU in Millions		Sep. 30, 2024 USD ($) MMBTU	Dec. 31, 2023 USD ($) MMBTU
Derivative [Line Items]
Current, Assets		$ 31,373	$ 74,225
Long-term, Assets		14,121	35,324
Current, Liabilities		147,866	185,788
Long-term, Liabilities		113,063	38,049
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Current, Assets		31,373	74,225
Long-term, Assets		14,121	35,324
Assets	[1]	45,494	109,549
Current, Liabilities		147,866	185,788
Long-term, Liabilities		113,063	38,049
Derivative Liability	[2]	$ 260,929	$ 223,837
Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBTU		237	301
Not Designated as Hedging Instrument [Member] | Electric Portfolio [Member]
Derivative [Line Items]
Assets		$ 39,585	$ 93,028
Derivative Liability		205,209	126,939
Not Designated as Hedging Instrument [Member] | Natural Gas Portfolio [Member]
Derivative [Line Items]
Assets		5,909	16,521
Derivative Liability		$ 55,720	$ 96,898
Not Designated as Hedging Instrument [Member] | Electric Generation Fuel [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBTU		254.9	315.6
Not Designated as Hedging Instrument [Member] | Purchased Electricity [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBTU		13.4	2.3
[1] _______________ 1 Balance sheet classification: Current and Long-term Unrealized gain on derivative instruments. 2 Balance sheet classification: Current and Long-term Unrealized loss on derivative instruments.

Accounting for Derivative Ins_5

Accounting for Derivative Instruments and Hedging Activities - Net Amount of Derivatives Reported in the Statement of Financial Position (Details) - Commodity Contract [Member] - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Gross Amount Recognized in the Statement of Financial Position	$ 45,494	$ 109,549
Gross Amounts Offset in the Statement of Financial Position	0	0
Assets	45,494	109,549
Commodity Contracts	(39,821)	(82,206)
Cash Collateral Received	0	0
Net Amount	5,673	27,343
Liabilities:
Gross Amount Recognized in the Statement of Financial Position	260,929	223,837
Gross Amounts Offset in the Statement of Financial Position	0	0
Derivative Liability	260,929	223,837
Commodity Contracts	(39,821)	(82,206)
Cash Collateral Posted	(6,030)	(84)
Net Amount	$ 215,078	$ 141,547

Accounting for Derivative Ins_6

Accounting for Derivative Instruments and Hedging Activities - Recognized in Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	$ (108,979)	$ 21,695	$ (131,712)	$ (201,230)
Not Designated as Hedging Instrument [Member]
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	(156,944)	23,329	(256,907)	(77,769)
Not Designated as Hedging Instrument [Member] | Electric Generation Fuel [Member] | Unrealized (Gain) Loss on Derivative Instruments, Net [Member]
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	(6,807)	38,966	(3,550)	(75,373)
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Electric Generation Fuel [Member]
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	(32,988)	(23,442)	(63,888)	51,253
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Purchased Electricity [Member]
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	(14,977)	25,076	(61,307)	72,208
Not Designated as Hedging Instrument [Member] | Electric | Unrealized (Gain) Loss on Derivative Instruments, Net [Member]
Derivative Instruments, (Loss) Gain [Line Items]
Unrealized (gain) loss on derivative instruments	$ (102,172)	$ (17,271)	$ (128,162)	$ (125,857)

Accounting for Derivative Ins_7

Accounting for Derivative Instruments and Hedging Activities - Contractual Contingent Liability (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	$ 371,100
Electric Portfolio [Member]
Derivative [Line Items]
Fair Value Liability	150,195	$ 66,895
Posted Collateral	9,742	12,429
Additional Collateral, Aggregate Fair Value	112,218	13,384
Natural Gas Portfolio [Member]
Derivative [Line Items]
Posted Collateral	0
Electric
Derivative [Line Items]
Posted Collateral	9,700
Credit Rating [Member] | Electric Portfolio [Member]
Derivative [Line Items]
Fair Value Liability	112,218	13,384
Posted Collateral	0	0
Additional Collateral, Aggregate Fair Value	112,218	13,384
Credit Rating [Member] | Natural Gas Portfolio [Member] | Standby Letters of Credit
Derivative [Line Items]
Posted Collateral	4,100
Requested Credit for Adequate Assurance [Member] | Electric Portfolio [Member]
Derivative [Line Items]
Fair Value Liability	31,565	53,427
Posted Collateral	0	0
Additional Collateral, Aggregate Fair Value	0	0
Forward Value of Contract [Member] | Electric Portfolio [Member]
Derivative [Line Items]
Fair Value Liability	6,412	84
Posted Collateral	$ 9,742	$ 12,429

Fair Value Measurements - Debt

Fair Value Measurements - Debt at at Carrying and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Liabilities:
Total long-term debt	$ 7,437,695	$ 7,036,642
Carrying Value [Member] | Level 2 [Member]
Liabilities:
Notes Receivable, Fair Value Disclosure	45,100	44,600
Subsidiaries [Member]
Liabilities:
Total long-term debt	5,977,376	5,184,047
Discounted cash flow [Member] | Fair Value [Member]
Liabilities:
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	7,396,449	6,855,503
Discounted cash flow [Member] | Fair Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	7,396,449	6,855,503
Discounted cash flow [Member] | Carrying Value [Member]
Liabilities:
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	7,437,695	7,036,642
Discounted cash flow [Member] | Carrying Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	7,437,695	7,036,642
Debt issuance costs	21,800	21,000
Discounted cash flow [Member] | Subsidiaries [Member] | Fair Value [Member]
Liabilities:
Total long-term debt	5,869,739	5,007,483
Discounted cash flow [Member] | Subsidiaries [Member] | Fair Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	5,869,739	5,007,483
Discounted cash flow [Member] | Subsidiaries [Member] | Carrying Value [Member]
Liabilities:
Total long-term debt	5,977,376	5,184,047
Discounted cash flow [Member] | Subsidiaries [Member] | Carrying Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	5,977,376	5,184,047
Debt issuance costs	$ 22,500	$ 21,200

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Compliance obligation	$ 70,431		$ 70,431			$ 168,879
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(86,530)	$ 39,165	(86,530)	$ 39,165	$ 5,063	31,113	$ 58,011	$ 115,951
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(97,624)	(12,551)	(148,522)	(47,613)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	1,217	3,808	1,741	3,852
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	4,814	(10,103)	29,138	(33,412)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0	0	387
Electric Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(88,470)	35,604	(88,470)	35,604	3,041	27,262	57,907	116,078
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(97,624)	(12,551)	(148,522)	(47,613)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	6,113	(9,752)	32,790	(33,078)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0	0	217
Gain (loss) on derivatives	(90,900)	(16,100)	(112,400)	(25,900)
Natural Gas Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	1,940	3,561	1,940	3,561	$ 2,022	3,851	$ 104	$ (127)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	1,217	3,808	1,741	3,852
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(1,299)	(351)	(3,652)	(334)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	$ 0	0	$ 170
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	45,494		45,494			109,549
Compliance obligation	70,431		70,431			168,879
Liabilities, Fair Value Disclosure	331,360		331,360			392,716
Fair Value, Recurring [Member] | Electric Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	39,585		39,585			93,028
Derivative Liability	205,209		205,209			126,939
Fair Value, Recurring [Member] | Natural Gas Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	5,909		5,909			16,521
Derivative Liability	55,720		55,720			96,898
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	21,210		21,210			53,901
Compliance obligation	70,431		70,431			168,879
Liabilities, Fair Value Disclosure	220,546		220,546			368,181
Fair Value, Recurring [Member] | Level 2 [Member] | Electric Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	17,906		17,906			42,254
Derivative Liability	95,060		95,060			103,427
Fair Value, Recurring [Member] | Level 2 [Member] | Natural Gas Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	3,304		3,304			11,647
Derivative Liability	55,055		55,055			95,875
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	24,284		24,284			55,648
Compliance obligation	0		0			0
Liabilities, Fair Value Disclosure	110,814		110,814			24,535
Fair Value, Recurring [Member] | Level 3 [Member] | Electric Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	21,679		21,679			50,774
Derivative Liability	110,149		110,149			23,512
Fair Value, Recurring [Member] | Level 3 [Member] | Natural Gas Portfolio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	2,605		2,605			4,874
Derivative Liability	$ 665		$ 665			$ 1,023

Fair Value Measurements - Valua

Fair Value Measurements - Valuation Techniques for Measurement with Unobservable Inputs (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) $ / MWh $ / MMBTU	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) $ / MWh $ / MMBTU	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value measurement, sensitivity analysis, hypothetical increase or decrease of market prices, result on fair value	10%		10%		10%
Fair Value Measurements, Sensitivity Analysis, Hypothetical Increase or Decrease of Market Prices, Result on Fair Value	$ 60,100,000		$ 60,100,000		$ 16,900,000
Impairment of Intangible Assets, Finite-lived			0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(86,530,000)	$ 39,165,000	(86,530,000)	$ 39,165,000	31,113,000	$ 5,063,000	$ 58,011,000	$ 115,951,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(97,624,000)	(12,551,000)	(148,522,000)	(47,613,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	1,217,000	3,808,000	1,741,000	3,852,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	4,814,000	(10,103,000)	29,138,000	(33,412,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0	0	387,000
Electric Portfolio [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) on derivatives	(90,900,000)	(16,100,000)	(112,400,000)	(25,900,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(88,470,000)	35,604,000	(88,470,000)	35,604,000	$ 27,262,000	3,041,000	57,907,000	116,078,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(97,624,000)	(12,551,000)	(148,522,000)	(47,613,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	6,113,000	(9,752,000)	32,790,000	(33,078,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0	$ 0	217,000
Electric Portfolio [Member] | Discounted cash flow [Member] | Low [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (per MWh) | $ / MWh			20.10		69.51
Electric Portfolio [Member] | Discounted cash flow [Member] | High [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (per MWh) | $ / MWh			149.85		188.63
Electric Portfolio [Member] | Discounted cash flow [Member] | Weighted Average [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Price (per MWh) | $ / MWh			73.29		99.55
Electric Portfolio [Member] | Fair Value, Recurring [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	39,585,000		$ 39,585,000		$ 93,028,000
Derivative Liability	205,209,000		205,209,000		126,939,000
Electric Portfolio [Member] | Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	21,679,000		21,679,000		50,774,000
Derivative Liability	110,149,000		110,149,000		23,512,000
Electric Portfolio [Member] | Fair Value, Recurring [Member] | Parent Company [Member] | Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	21,679,000		21,679,000		50,774,000
Derivative Liability	110,149,000		110,149,000		23,512,000
Natural Gas Portfolio [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	1,940,000	3,561,000	1,940,000	3,561,000	$ 3,851,000	$ 2,022,000	$ 104,000	$ (127,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Regulatory Assets (Liabilities)	1,217,000	3,808,000	1,741,000	3,852,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(1,299,000)	(351,000)	(3,652,000)	(334,000)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	$ 0	$ 0	$ 170,000
Natural Gas Portfolio [Member] | Discounted cash flow [Member] | Low [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Price Per Millions of BTU | $ / MMBTU			2.10		2.20
Natural Gas Portfolio [Member] | Discounted cash flow [Member] | High [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Price Per Millions of BTU | $ / MMBTU			5.86		6.28
Natural Gas Portfolio [Member] | Discounted cash flow [Member] | Weighted Average [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Price Per Millions of BTU | $ / MMBTU			4.50		3.55
Natural Gas Portfolio [Member] | Fair Value, Recurring [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	5,909,000		$ 5,909,000		$ 16,521,000
Derivative Liability	55,720,000		55,720,000		96,898,000
Natural Gas Portfolio [Member] | Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	2,605,000		2,605,000		4,874,000
Derivative Liability	665,000		665,000		1,023,000
Natural Gas Portfolio [Member] | Fair Value, Recurring [Member] | Parent Company [Member] | Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets	2,605,000		2,605,000		4,874,000
Derivative Liability	$ 665,000		$ 665,000		$ 1,023,000

Retirement Benefits - Net Perio

Retirement Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Qualified Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost			$ 13,962		$ 18,530
Defined Benefit Plan, Interest Cost			23,364		32,375
Qualified Pension Benefits [Member] | Parent Company [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	$ 4,654	$ 4,632	13,962	$ 13,898
Defined Benefit Plan, Interest Cost	7,788	8,094	23,364	24,281
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(13,724)	(12,660)	(41,172)	(37,980)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	(671)	(612)	(2,013)	(1,836)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	(1,953)	(546)	(5,859)	(1,637)
Qualified Pension Benefits [Member] | Subsidiaries [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	4,654	4,632	13,962	13,898
Defined Benefit Plan, Interest Cost	7,788	8,094	23,364	24,281
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(13,724)	(12,660)	(41,172)	(37,981)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	(1,282)	66	(3,846)	198
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost			0		143
Defined Benefit Plan, Interest Cost			1,027		1,589
Supplemental Employee Retirement Plan [Member] | Parent Company [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	0	0	0	141
Defined Benefit Plan, Interest Cost	342	370	1,027	1,219
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	146
Defined Benefit Plan, Amortization of Gain (Loss)	(10)	0	(31)	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	332	370	996	1,506
Supplemental Employee Retirement Plan [Member] | Subsidiaries [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	0	0	0	141
Defined Benefit Plan, Interest Cost	342	370	1,027	1,219
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0	146
Defined Benefit Plan, Amortization of Gain (Loss)	(5)	0	(16)	44
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	337	370	1,011	1,550
Other Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost			148		184
Defined Benefit Plan, Interest Cost			305		$ 439
Other Benefit [Member] | Parent Company [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	47	44	148	138
Defined Benefit Plan, Interest Cost	97	99	305	330
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(61)	(64)	(216)	(223)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	8	7	25	21
Defined Benefit Plan, Amortization of Gain (Loss)	(24)	(57)	(105)	(158)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	67	29	157	108
Other Benefit [Member] | Subsidiaries [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Service Cost	47	44	148	138
Defined Benefit Plan, Interest Cost	97	99	305	330
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(61)	(64)	(216)	(223)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	8	7	25	21
Defined Benefit Plan, Amortization of Gain (Loss)	(22)	(64)	(105)	(173)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	$ 69	$ 22	$ 157	$ 93

Retirement Benefits - Change in

Retirement Benefits - Change in Net Benefit Obligation (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Qualified Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	$ 609,103	$ 589,278
Defined Benefit Plan, Service Cost	13,962	18,530
Defined Benefit Plan, Interest Cost	23,364	32,375
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	1,450	8,469
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(34,607)	(38,258)
Administrative Expense	0	(1,291)
Defined Benefit Plan, Benefit Obligation, Ending Balance	613,272	609,103
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	26,824	32,046
Defined Benefit Plan, Service Cost	0	143
Defined Benefit Plan, Interest Cost	1,027	1,589
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0	(2,772)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	0	(661)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(1,498)	(3,521)
Administrative Expense	0	0
Defined Benefit Plan, Benefit Obligation, Ending Balance	26,353	26,824
Other Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Beginning Balance	8,597	9,015
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	78
Defined Benefit Plan, Service Cost	148	184
Defined Benefit Plan, Interest Cost	305	439
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	161	(52)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(868)	(1,067)
Administrative Expense	0	0
Defined Benefit Plan, Benefit Obligation, Ending Balance	8,343	8,597
Qualified Plan [Member] | Qualified Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0	0
Nonqualified Plan [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	$ 0	$ 0

Retirement Benefits - Activity

Retirement Benefits - Activity (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2024
Subsidiaries [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Interest Credit	4%
UA represented [Member] | employer contribution [Member] | Subsidiaries [Member] | Collective Bargaining Arrangement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4%
IBEW represented | employer contribution [Member] | Subsidiaries [Member] | Collective Bargaining Arrangement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	4%
Qualified Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 18	$ 18
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 1.5	$ 3
Forecast [Member] | Qualified Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate expected contributions			$ 18
Forecast [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate expected contributions			2
Forecast [Member] | Other Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate expected contributions			$ 0.2

Regulation and Rates (Details)

Regulation and Rates (Details) - USD ($) $ in Thousands									3 Months Ended		9 Months Ended		12 Months Ended					13 Months Ended
	Nov. 01, 2024	Apr. 30, 2024	Jan. 01, 2024	Nov. 01, 2023	Jan. 11, 2023	Dec. 31, 2022	Dec. 22, 2022	Nov. 01, 2022	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2026	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024	Jan. 01, 2018
Regulatory Assets [Line Items]
Income tax (benefit) expense									$ (13,545)	$ (1,908)	$ (1,545)	$ 11,699
Depreciation and amortization									197,975	189,298	585,317	565,506
Other regulatory assets									993,032		993,032					$ 1,163,551
Revenues									927,544	941,020	3,475,929	3,445,835
Compliance obligation									70,431		70,431					168,879
Subsidiaries [Member]
Regulatory Assets [Line Items]
Income tax (benefit) expense									(18,408)	695	3,922	2,244
Annual Power Cost Variability, Interest											2,300	3,600
Depreciation and amortization									196,298	$ 187,622	580,304	560,480
Annual Power Cost Variability, Amount		$ (22,200)
Other regulatory assets									993,032		993,032					1,163,551
Purchased gas adjustment receivable						$ (3,536)			(60,483)		(60,483)					(132,082)	$ (3,536)
Rate Plan, number of years					2 years
Compliance obligation									70,431		70,431					168,879
Deferred Emission Compliance Costs, Regulatory Liability									89,900		89,900
Subsidiaries [Member] | Under-collection [Member]
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount											111,100	(66,200)				51,100	110,100
Subsidiaries [Member] | Under-collection [Member] | Companys share [Member]
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount																26,200	39,000
Subsidiaries [Member] | Under-collection [Member] | Customer's share [Member]
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount											75,500	(38,500)				24,900	71,100
Subsidiaries [Member] | Under-collection [Member] | Customer's share plus interest
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount																22,200	76,400
Subsidiaries [Member] | Maximum Power
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount																20,000	$ 20,000
Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Storm Damage Costs Incurred During Period											13,300	6,100
Public Utilities, Rate Case, Deferred Storm Costs Threshold																			$ 10,000
Public Utilities, Rate Case, Deferred Storm Qualifying Costs																			$ 500
Compliance obligation									15,000		15,000
Subsidiaries [Member] | Natural Gas
Regulatory Assets [Line Items]
Deferred Emission Compliance Auction Proceeds, Regulatory Asset									$ 26,900		26,900
General Rate Case [Member] | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount																$ 247,000
Public Utilities, Approved Rate Increase (Decrease), Percentage																10.80%
General Rate Case [Member] | Subsidiaries [Member] | Natural Gas
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount																$ 70,800
Public Utilities, Approved Rate Increase (Decrease), Percentage																6.40%
General Rate Case [Member] | Maximum [Member] | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Debt Capital Structure, Percentage							7.16%
Public Utilities, Approved Debt Capital Structure, Net of Tax, Percentage							6.62%
Public Utilities, Approved Equity Capital Structure, Percentage							49%
Public Utilities, Approved Return on Equity, Percentage							9.40%
Decoupling Mechanism [Member] | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Contract with Customer, Liability, Revenue Recognized											100	0
Decoupling Mechanism [Member] | Subsidiaries [Member] | Natural Gas
Regulatory Assets [Line Items]
Contract with Customer, Liability, Revenue Recognized											0	0
Purchased Gas Adjustment [Member] | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount				$ (309,400)				$ 155,300
Purchased natural gas costs											287,111					$ 404,897
Purchased natural gas costs, recoverable											(210,102)					(521,882)
Purchased natural gas adjustment, interest											(5,410)					(7,639)
Purchased natural gas costs, credit for CP settlement				28,100		$ 24,200					0					$ (3,922)
Purchased natural gas costs, commodity deferrals				142,800
Purchased Gas Adjustment [Member] | Subsidiaries [Member] | Subsequent Event
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 124,400
Power Cost Only Rate Case | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount					$ 0
Purchased Gas Adjustment, Schedule 101 | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount				(93,900)				142,100
Purchased Gas Adjustment, Schedule 101 | Subsidiaries [Member] | Subsequent Event
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	(2,600)
purchased gas adjustment, Schedule 106 106B | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount				$ (215,500)				$ 13,200
purchased gas adjustment, Schedule 106 106B | Subsidiaries [Member] | Subsequent Event
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 127,000
Climate Commitment Act | Subsidiaries [Member] | Natural Gas
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount			$ 29,100
Storm that occurred in 2022 | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Storm Damage Costs Deferred During Period												2,100
Storm that occurred in 2023 | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Storm Damage Costs Deferred During Period												$ 0
Storm that occurred in 2024 | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Storm Damage Costs Deferred During Period											$ 2,800
Forecast [Member] | Subsidiaries [Member]
Regulatory Assets [Line Items]
Annual Power Cost Variability, Amount															$ 98,200
Public Utilities, Allowance for Funds Used During Construction, Rate													7.99%	7.65%
Forecast [Member] | General Rate Case [Member] | Subsidiaries [Member] | Electric
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount															$ 33,100
Public Utilities, Approved Rate Increase (Decrease), Percentage													8.50%	6.70%	1.30%
Forecast [Member] | General Rate Case [Member] | Subsidiaries [Member] | Natural Gas
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount															$ 19,500
Public Utilities, Approved Rate Increase (Decrease), Percentage													2.10%	19%	1.70%
Forecast [Member] | General Rate Case [Member] | Maximum [Member] | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Return on Equity, Percentage													10.50%	9.95%
Forecast [Member] | PCA Mechanism [Member] | Subsidiaries [Member]
Regulatory Assets [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage																		0.90%

Regulation and Rates - Schedule

Regulation and Rates - Schedule of Power Cost Adjustment Mechanism (Details) - Subsidiaries [Member] $ in Millions		9 Months Ended		12 Months Ended
	Apr. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount	$ (22.2)
Annual Power Cost Variability, Interest		$ 2.3	$ 3.6
Forecast [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount				$ 98.2
Under-collection [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount		111.1	(66.2)		$ 51.1	$ 110.1
Under-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount					26.2	39
Under-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount		$ 75.5	$ (38.5)		24.9	71.1
Under-collection [Member] | Customer's share plus interest
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount					22.2	76.4
Maximum Power
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability, Amount					$ 20	$ 20
Range 1 [Member] | Over-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		1
Range 1 [Member] | Over-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0
Range 1 [Member] | Under-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		1
Range 1 [Member] | Under-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0
Range 2 [Member] | Over-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.35
Range 2 [Member] | Over-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.65
Range 2 [Member] | Under-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.50
Range 2 [Member] | Under-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.50
Range 3 [Member] | Over-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.10
Range 3 [Member] | Over-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.90
Range 3 [Member] | Under-collection [Member] | Companys share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.10
Range 3 [Member] | Under-collection [Member] | Customer's share [Member]
Regulatory Assets and Liabiliaties [Line Items]
Annual Power Cost Variability		0.90

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Compliance obligation	$ 70,431	$ 168,879
Subsidiaries [Member]
Loss Contingencies [Line Items]
Contractual Obligation	2,700,000
Compliance obligation	70,431	$ 168,879
Subsidiaries [Member] | Electric
Loss Contingencies [Line Items]
Compliance obligation	$ 15,000
Colstrip Units 1 and 2 [Member] | Colstrip Units 1 and 2 [Member]
Loss Contingencies [Line Items]
Ownership interest (percent)	50%
Colstrip Units 3 and 4 [Member] | Colstrip Units 3 and 4 [Member]
Loss Contingencies [Line Items]
Ownership interest (percent)	25%

Leases (Details)

Leases (Details) - Subsidiaries [Member] $ in Millions	Sep. 30, 2027 USD ($)	Aug. 31, 2027 USD ($)	Dec. 31, 2025 USD ($)	Oct. 01, 2025 USD ($)	Sep. 20, 2023 MW
Lessor, Lease, Description [Line Items]
Lessee, Finance Lease, Lease Not yet Commenced, Capacity | MW					132.5
Forecast [Member]
Lessor, Lease, Description [Line Items]
Lessee, Finance Lease, Lease Not yet Commenced, Term of Contract				5 years
Lessee, Finance Lease, Lease Not Yet Commenced, Fixed Consideration				$ 91
Forecast [Member] | Mt Vernon Battery Storage
Lessor, Lease, Description [Line Items]
Lessee, Finance Lease, Lease Not yet Commenced, Term of Contract	25 years
Lessee, Finance Lease, Lease Not Yet Commenced, Fixed Consideration	$ 856.2
Forecast [Member] | Greenwater Battery Storage
Lessor, Lease, Description [Line Items]
Lessee, Finance Lease, Lease Not yet Commenced, Term of Contract		20 years
Lessee, Finance Lease, Lease Not Yet Commenced, Fixed Consideration		$ 744
Forecast [Member] | Puyallup Operation Training Facility
Lessor, Lease, Description [Line Items]
Lessee, Finance Lease, Lease Not yet Commenced, Term of Contract			20 years
Lessee, Finance Lease, Lease Not Yet Commenced, Fixed Consideration			$ 116

Leases - Supplemental balance s

Leases - Supplemental balance sheet information related to leases (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Lessee, Operating Lease, Description [Abstract]
Operating Lease, Right-of-Use Asset	$ 184,769	$ 194,321
Operating Lease, Liability, Current	22,517	21,629
Operating Lease, Liability, Noncurrent	$ 170,311	$ 180,754

Other - Narrative (Details)

Other - Narrative (Details)						9 Months Ended
	Aug. 30, 2024 USD ($)	Jun. 17, 2024 USD ($)	Jan. 26, 2024 USD ($)	Dec. 22, 2023 USD ($)	Dec. 01, 2023 USD ($) wind_turbine	Sep. 30, 2024 USD ($)	Dec. 31, 2026 MW	Dec. 31, 2025 MW	Jun. 11, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period						$ 371,100,000
Short-term debt						371,100,000				$ 598,100,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress						1,717,323,000				1,156,265,000
Subsidiaries [Member]
Debt Instrument [Line Items]
Commercial Paper						0
Short-term debt						0				336,600,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress						1,717,323,000				$ 1,156,265,000
Proceeds from Contributed Capital		$ 292,800,000
Subsidiaries [Member] | Beaver Creek Wind Project
Debt Instrument [Line Items]
Asset Acquisition, Price of Acquisition, Expected			$ 145,400,000
Subsidiaries [Member] | Appaloosa Solar Project
Debt Instrument [Line Items]
Asset Acquisition, Price of Acquisition, Expected	$ 266,800,000
Subsidiaries [Member] | GE Renewables North America, LLC | Beaver Creek Wind Project
Debt Instrument [Line Items]
Asset Acquisition, Price of Acquisition, Expected					$ 266,900,000
Subsidiaries [Member] | Beaver Creek Wind Project
Debt Instrument [Line Items]
Public Utilities, Property, Plant and Equipment, Construction Work in Progress						461,500,000
Number of Windmills | wind_turbine					88
Asset Retirement Obligation						19,200,000
Subsidiaries [Member] | Beaver Creek Wind Project | Forecast [Member]
Debt Instrument [Line Items]
Nameplate Capacity | MW								248
Subsidiaries [Member] | Beaver Creek Wind Project | GE Renewables North America, LLC
Debt Instrument [Line Items]
Asset Acquisition, Consideration Transferred						229,500,000
Subsidiaries [Member] | Beaver Creek Wind Project | Caithness Beaver Creek, LLC
Debt Instrument [Line Items]
Asset Acquisition, Consideration Transferred					$ 44,600,000	23,800,000
Subsidiaries [Member] | Appaloosa Solar Project
Debt Instrument [Line Items]
Public Utilities, Property, Plant and Equipment, Construction Work in Progress						20,300,000
Subsidiaries [Member] | Appaloosa Solar Project | Forecast [Member]
Debt Instrument [Line Items]
Nameplate Capacity | MW							142
Subsidiaries [Member] | Appaloosa Solar Project | HQC Solar Holdings 1, LLC
Debt Instrument [Line Items]
Asset Acquisition, Consideration Transferred				$ 20,300,000
Parent Company [Member]
Debt Instrument [Line Items]
Proceeds from Contributed Capital		$ 292,800,000
Working Capital Needs [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period						0
Energy Hedging Activities | Subsidiaries [Member] | Standby Letters of Credit
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						150,000,000
Line of Credit Facility, Current Borrowing Capacity						4,100,000
Long-Term Transmission Contract | Subsidiaries [Member] | Letter of Credit
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity						1,900,000
Purchase Power Contract | Subsidiaries [Member]
Debt Instrument [Line Items]
Posted Collateral						15,200,000
Purchase Power Contract | Subsidiaries [Member] | Standby Letters of Credit | Purchase Power Contract 1
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity						24,000,000
Purchase Power Contract | Subsidiaries [Member] | Standby Letters of Credit | Purchase Power Contract 2
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity						$ 13,500,000
5.330% Senior Secured Note Due 2034 | Senior Secured Note | Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross									$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage									5.33%
5.685% Senior Secured Note Due 2054 | Senior Secured Note | Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross									$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage									5.685%