Puget Energy (PSD) 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2013
Entity Information [Line Items]	'
Entity Registrant Name	'PUGET ENERGY INC /WA
Entity Central Index Key	'0001085392
Current Fiscal Year End Date	'--12-31
Entity Well-known Seasoned Issuer	'No
Entity Voluntary Filers	'Yes
Entity Current Reporting Status	'No
Entity Filer Category	'Non-accelerated Filer
Entity Common Stock, Shares Outstanding	200
Document Fiscal Year Focus	'2013
Document Fiscal Period Focus	'Q3
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	30-Sep-13
Subsidiaries [Member]	'
Entity Information [Line Items]	'
Entity Registrant Name	'PUGET SOUND ENERGY INC
Entity Central Index Key	'0000081100
Current Fiscal Year End Date	'--12-31
Entity Well-known Seasoned Issuer	'Yes
Entity Voluntary Filers	'No
Entity Current Reporting Status	'Yes
Entity Filer Category	'Non-accelerated Filer
Entity Common Stock, Shares Outstanding	85,903,791
Document Fiscal Year Focus	'2013
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	30-Sep-13

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenue:	'	'	'	'
Electric	$477,483	$455,726	$1,553,774	$1,537,764
Gas	120,796	123,984	686,289	767,773
Other	69	-955	589	347
Total operating revenue	598,348	578,755	2,240,652	2,305,884
Energy costs:	'	'	'	'
Purchased electricity	92,774	85,933	380,360	441,145
Electric generation fuel	76,689	64,798	176,513	154,596
Residential exchange	-13,949	-14,038	-51,464	-52,675
Purchased gas	45,889	51,311	315,359	381,291
Unrealized (gain) loss on derivative instruments, net	-8,888	-67,490	-57,203	-126,840
Utility operations and maintenance	129,963	120,386	389,484	376,627
Non-utility expense and other	-1,640	-54	-3,592	738
Depreciation	91,834	85,314	270,314	248,872
Amortization	5,365	16,491	17,542	41,381
Conservation amortization	20,645	20,650	77,220	83,570
Taxes other than income taxes	59,623	62,192	213,260	235,021
Total operating expenses	498,305	425,493	1,727,793	1,783,726
Operating income	100,043	153,262	512,859	522,158
Other income (deductions):	'	'	'	'
Other income	9,197	6,891	32,052	40,165
Other expense	-1,844	-2,775	-4,840	-8,475
Non-hedged interest rate derivative expense	-470	1,512	1,790	-5,258
Interest charges:	'	'	'	'
AFUDC	2,338	5,252	10,148	17,234
Interest expense	-94,788	-96,507	-299,521	-299,672
Income (loss) before income taxes	14,476	67,635	252,488	266,152
Income tax (benefit) expense	5,936	20,943	75,569	73,289
Net income (loss)	8,540	46,692	176,919	192,863
Subsidiaries [Member]	'	'	'	'
Operating revenue:	'	'	'	'
Electric	477,483	455,726	1,553,774	1,537,764
Gas	120,796	123,984	686,289	767,773
Other	69	-99	479	1,203
Total operating revenue	598,348	579,611	2,240,542	2,306,740
Energy costs:	'	'	'	'
Purchased electricity	92,774	85,933	380,360	441,145
Electric generation fuel	76,689	64,798	176,513	154,596
Residential exchange	-13,949	-14,038	-51,464	-52,675
Purchased gas	45,889	51,311	315,359	381,291
Unrealized (gain) loss on derivative instruments, net	-8,888	-65,594	-54,252	-115,309
Utility operations and maintenance	129,963	120,386	389,484	376,627
Non-utility expense and other	2,318	2,161	8,439	7,665
Depreciation	91,834	85,314	270,314	248,872
Amortization	5,365	16,491	17,542	41,381
Conservation amortization	20,645	20,650	77,220	83,570
Taxes other than income taxes	59,623	62,192	213,260	235,021
Total operating expenses	502,263	429,604	1,742,775	1,802,184
Operating income	96,085	150,007	497,767	504,556
Other income (deductions):	'	'	'	'
Other income	9,197	6,891	32,051	40,153
Other expense	-1,844	-2,775	-4,840	-8,475
Interest charges:	'	'	'	'
AFUDC	2,338	5,252	10,148	17,234
Interest expense	-64,614	-61,524	-196,363	-184,595
Interest expense on parent note	-27	-34	-88	-167
Income (loss) before income taxes	41,135	97,817	338,675	368,706
Income tax (benefit) expense	14,530	30,949	105,470	108,250
Net income (loss)	$26,605	$66,868	$233,205	$260,456

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Parent [Line Items]	'	'	'	'
Reclassification of net unrealized loss on energy derivative instruments during the period, net of tax	$0	($137)	$57	$98
Net income (loss)	8,540	46,692	176,919	192,863
Other comprehensive income (loss):	'	'	'	'
Net unrealized gain (loss) from pension and postretirement plans, net of tax	-393	-1,248	367	-1,457
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0	255	-107	182
Other comprehensive income (loss)	1,204	62	2,052	9,376
Comprehensive income (loss)	9,744	46,754	178,971	202,239
PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Net current-period other comprehensive income (loss)	1,204	'	2,052	'
Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Reclassification of net unrealized loss on energy derivative instruments during the period, net of tax	0	784	976	3,364
Net income (loss)	26,605	66,868	233,205	260,456
Other comprehensive income (loss):	'	'	'	'
Net unrealized gain (loss) from pension and postretirement plans, net of tax	3,406	2,439	8,671	6,082
Net current-period other comprehensive income (loss)	3,485	'	10,719	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0	1,456	1,811	6,247
Amortization Of Financing Cash Flow Hedge Contracts To Earnings During Period Net Of Tax	79	79	237	238
Other comprehensive income (loss)	3,485	3,974	10,719	12,567
Comprehensive income (loss)	30,090	70,842	243,924	273,023
Amortization Of Financing Cash Flow Hedge Contracts To Earnings Tax	43	43	128	128
Interest Rate Contract [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Reclassification of net unrealized (gain) loss on interest rate swaps during the period, net of tax	811	1,055	2,526	10,651
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Interest Rate Contract [Member] | PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Net current-period other comprehensive income (loss)	811	'	2,526	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Energy Related Derivative [Member] | PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Net current-period other comprehensive income (loss)	0	'	-107	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Energy Related Derivative [Member] | Subsidiaries [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Net current-period other comprehensive income (loss)	79	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	-1,204	'	-3,600	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	-3,485	'	-12,266	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Interest Rate Contract [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	-811	'	-2,526	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Interest Rate Contract [Member] | Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	-79	'	-237	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Energy Related Derivative [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	0	'	107	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Energy Related Derivative [Member] | Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	'	'	-1,810	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	-393	'	-1,181	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net income (loss)	($3,406)	'	($10,219)	'

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Parent [Line Items]	'	'	'	'
Reclassification of net unrealized loss on interest rate swaps during the period, net of tax	$436	$568	$1,360	$5,735
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	5,936	20,943	75,569	73,289
Net unrealized gain (loss) from pension and postretirement plans, tax	212	-672	-197	-784
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0	255	-107	182
Reclassification of net unrealized loss on energy derivative instruments during the period, net of tax	0	-137	57	98
PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net current-period other comprehensive income (loss)	1,204	'	2,052	'
Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net current-period other comprehensive income (loss)	3,485	'	10,719	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	14,530	30,949	105,470	108,250
Net unrealized gain (loss) from pension and postretirement plans, tax	1,834	1,313	4,669	3,275
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0	1,456	1,811	6,247
Amortization Of Financing Cash Flow Hedge Contracts To Earnings Tax	43	43	128	128
Reclassification of net unrealized loss on energy derivative instruments during the period, net of tax	0	784	976	3,364
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	-212	'	-636	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | Subsidiaries [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	-1,834	'	-5,501	'
Energy Related Derivative [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net current-period other comprehensive income (loss)	0	'	-107	'
Energy Related Derivative [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Subsidiaries [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net current-period other comprehensive income (loss)	79	'	'	'
Energy Related Derivative [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	0	'	-57	'
Energy Related Derivative [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Subsidiaries [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	0	'	976	'
Interest Rate Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | PUGET ENERGY [Member]	'	'	'	'
Parent [Line Items]	'	'	'	'
Net current-period other comprehensive income (loss)	811	'	2,526	'
Interest Rate Contract [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | PUGET ENERGY [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	436	'	1,360	'
Interest Rate Contract [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Subsidiaries [Member]	'	'	'	'
Other comprehensive income (loss):	'	'	'	'
Income tax (benefit) expense	$43	'	($129)	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Utility plant (at original cost, including construction work in progress):	'	'
Electric plant	$6,970,492	$6,750,400
Gas plant	2,496,438	2,385,784
Common plant	501,006	487,931
Less: Accumulated depreciation and amortization	-1,285,287	-1,067,424
Net utility plant	8,682,649	8,556,691
Other property and investments:	'	'
Goodwill	1,656,513	1,656,513
Other property and investments	101,754	112,367
Total other property and investments	1,758,267	1,768,880
Current assets:	'	'
Cash and cash equivalents	14,033	135,542
Restricted cash	7,765	3,700
Accounts receivable, net of allowance for doubtful accounts	223,707	321,480
Unbilled revenue	127,759	204,359
Materials and supplies, at average cost	88,778	82,353
Fuel and gas inventory, at average cost	85,163	88,953
Unrealized gain on derivative instruments	6,643	6,869
Income taxes	0	4,796
Prepaid expense and other	38,223	13,571
Power contract acquisition adjustment gain	48,649	50,785
Deferred income taxes	26,838	53,437
Total current assets	667,558	965,845
Other long-term and regulatory assets:	'	'
Regulatory asset for deferred income taxes	139,087	119,844
Power cost adjustment mechanism	0	3,773
Regulatory assets related to power contracts	34,450	37,655
Other regulatory assets	806,747	815,785
Unrealized gain on derivative instruments	6,644	14,814
Power contract acquisition adjustment gain	405,599	456,225
Other	86,820	95,763
Total other long-term and regulatory assets	1,479,347	1,543,859
Total assets	12,587,821	12,835,275
Capitalization:	'	'
Common stock	0	0
Additional paid-in capital	3,308,957	3,308,957
Earnings reinvested in the business	257,204	208,100
Accumulated other comprehensive income (loss), net of tax	-30,777	-32,829
Total common shareholder's equity	3,535,384	3,484,228
Long-term debt:	'	'
First mortgage bonds and senior notes	3,351,412	3,351,412
Pollution control bonds	161,860	161,860
Junior subordinated notes	250,000	250,000
Long-term debt	1,699,000	1,834,000
Debt discount	-232,579	-264,072
Total long-term debt	5,229,693	5,333,200
Total capitalization	8,765,077	8,817,428
Current liabilities:	'	'
Accounts payable	238,224	321,755
Short-term debt	129,000	181,000
Current Maturities of long-term debt	10,000	13,000
Purchased gas adjustment liability	4,651	32,587
Accrued expenses:	'	'
Taxes	75,146	95,623
Salaries and wages	36,850	38,438
Interest	74,314	82,262
Unrealized loss on derivative instruments	102,847	177,519
Power contract acquisition adjustment loss	3,938	3,902
Other	66,966	72,799
Total current liabilities	741,936	1,018,885
Long-term and regulatory liabilities:	'	'
Deferred income taxes	1,330,957	1,261,636
Unrealized loss on derivative instruments	54,950	83,276
Power Cost Adjustment Mechanism	16,489	0
Regulatory liabilities	658,698	600,697
Regulatory liabilities related to power contracts	454,248	507,009
Power contract acquisition adjustment loss	30,512	33,753
Other deferred credits	534,954	512,591
Total long-term and regulatory liabilities	3,080,808	2,998,962
Commitments and contingencies	'	'
Total capitalization and liabilities	12,587,821	12,835,275
Subsidiaries [Member]	'	'
Utility plant (at original cost, including construction work in progress):	'	'
Electric plant	9,232,702	9,048,356
Gas plant	3,104,751	2,998,188
Common plant	562,067	555,549
Less: Accumulated depreciation and amortization	-4,216,871	-4,045,402
Net utility plant	8,682,649	8,556,691
Other property and investments:	'	'
Other property and investments	92,923	103,646
Total other property and investments	92,923	103,646
Current assets:	'	'
Cash and cash equivalents	13,863	135,530
Restricted cash	7,765	3,700
Accounts receivable, net of allowance for doubtful accounts	223,766	321,685
Unbilled revenue	127,759	204,359
Materials and supplies, at average cost	88,778	82,353
Fuel and gas inventory, at average cost	82,866	85,547
Unrealized gain on derivative instruments	6,643	6,869
Income taxes	0	4,796
Prepaid expense and other	38,162	13,413
Deferred income taxes	41,081	68,015
Total current assets	630,683	926,267
Other long-term and regulatory assets:	'	'
Regulatory asset for deferred income taxes	138,564	119,279
Power cost adjustment mechanism	0	3,773
Other regulatory assets	806,486	813,171
Unrealized gain on derivative instruments	6,644	14,814
Other	78,459	90,330
Total other long-term and regulatory assets	1,030,153	1,041,367
Total assets	10,436,408	10,627,971
Capitalization:	'	'
Common stock	859	859
Additional paid-in capital	3,246,205	3,246,205
Earnings reinvested in the business	228,041	344,280
Accumulated other comprehensive income (loss), net of tax	-176,479	-187,198
Total common shareholder's equity	3,298,626	3,404,146
Long-term debt:	'	'
First mortgage bonds and senior notes	3,351,412	3,351,412
Pollution control bonds	161,860	161,860
Junior subordinated notes	250,000	250,000
Debt discount	-14	-14
Total long-term debt	3,763,258	3,763,258
Total capitalization	7,061,884	7,167,404
Current liabilities:	'	'
Accounts payable	238,282	321,952
Short-term debt	129,000	181,000
Short-term note owed to parent	29,598	29,598
Current Maturities of long-term debt	10,000	13,000
Purchased gas adjustment liability	4,651	32,587
Accrued expenses:	'	'
Taxes	75,146	95,623
Salaries and wages	36,850	38,438
Interest	56,790	55,806
Unrealized loss on derivative instruments	96,245	170,948
Other	66,648	69,882
Total current liabilities	743,210	1,008,834
Long-term and regulatory liabilities:	'	'
Deferred income taxes	1,378,195	1,274,602
Unrealized loss on derivative instruments	46,830	68,323
Power Cost Adjustment Mechanism	16,489	0
Regulatory liabilities	656,098	596,324
Other deferred credits	533,702	512,484
Total long-term and regulatory liabilities	2,631,314	2,451,733
Commitments and contingencies	'	'
Total capitalization and liabilities	$10,436,408	$10,627,971

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
ASSETS	'	'
Construction work in progress	$329,303	$766,035
Current assets:	'	'
Allowance for doubtful accounts	5,568	9,932
Common shareholderbs equity:	'	'
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 (in shares)	200	200
Subsidiaries [Member]	'	'
ASSETS	'	'
Construction work in progress	329,303	766,035
Current assets:	'	'
Allowance for doubtful accounts	$5,568	$9,932
Common shareholderbs equity:	'	'
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 (in shares)	85,903,791	85,903,791

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities:	'	'
Net income (loss)	$176,919	$192,863
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation	270,314	248,872
Amortization	17,542	41,381
Conservation amortization	77,220	83,570
Deferred income taxes and tax credits, net	75,572	69,655
Net unrealized (gain) loss on derivative instruments	-60,120	-140,078
Funding of pension liability	-15,300	-17,100
Derivative contracts classified as financing activities due to merger	25,976	65,906
AFUDC - Equity	-14,550	-20,215
Regulatory Assets	-107,379	-130,537
Regulatory liabilities	29,401	20,395
Other long-term assets	16,422	6,780
Other long-term liabilities	72,001	59,661
Change in certain current assets and liabilities:	'	'
Accounts receivable and unbilled revenue	172,981	225,224
Materials and supplies	-6,425	-9,213
Fuel and gas inventory	2,681	21,847
Income taxes	4,796	5,838
Prepayments and other	-24,749	-21,104
Purchased gas adjustment	-27,936	12,130
Accounts payable	-64,274	-90,251
Taxes payable	-20,477	-21,349
Accrued expenses and other	-21,353	21,864
Net cash provided by operating activities	579,262	626,139
Investing activities:	'	'
Construction expenditures - excluding equity AFUDC	-450,792	-570,107
Proceeds from disposition of assets	108,362	0
Restricted cash	-4,065	579
Other	-4,912	-33,617
Net cash used in investing activities	-351,407	-603,145
Financing activities:	'	'
Change in short-term debt and leases, net	-57,684	75,316
Dividends paid	-127,815	-88,594
Long-term notes and bonds issued	161,860	1,314,000
Redemption of bonds and notes	-299,860	-1,273,000
Derivative contracts classified as financing activities due to merger	-25,976	-65,906
Issuance cost of bonds and other	111	-4,567
Net cash provided by (used in) financing activities	-349,364	-42,751
Net increase (decrease) in cash and cash equivalents	-121,509	-19,757
Cash and cash equivalents at beginning of period	135,542	37,235
Cash and cash equivalents at end of period	14,033	17,478
Supplemental cash flow information:	'	'
Cash payments for interest (net of capitalized interest)	252,202	242,788
Cash payments (refunds) for income taxes	-4,500	-1,898
Subsidiaries [Member]	'	'
Operating activities:	'	'
Net income (loss)	233,205	260,456
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation	270,314	248,872
Amortization	17,542	41,381
Conservation amortization	77,220	83,570
Deferred income taxes and tax credits, net	105,470	104,615
Net unrealized (gain) loss on derivative instruments	-54,252	-115,309
Funding of pension liability	-15,300	-17,100
AFUDC - Equity	-14,550	-20,215
Regulatory Assets	-107,379	-130,537
Regulatory liabilities	29,401	20,395
Other long-term assets	20,140	9,818
Other long-term liabilities	51,266	45,228
Change in certain current assets and liabilities:	'	'
Accounts receivable and unbilled revenue	173,127	224,397
Materials and supplies	-6,425	-9,213
Fuel and gas inventory	2,681	21,847
Income taxes	4,796	5,838
Prepayments and other	-24,749	-21,104
Purchased gas adjustment	-27,936	12,130
Accounts payable	-64,414	-89,696
Taxes payable	-20,477	-21,349
Accrued expenses and other	-10,427	-6,233
Net cash provided by operating activities	639,253	647,791
Investing activities:	'	'
Construction expenditures - excluding equity AFUDC	-450,792	-570,107
Proceeds from disposition of assets	108,362	0
Restricted cash	-4,065	579
Other	-4,405	-12,780
Net cash used in investing activities	-350,900	-582,308
Financing activities:	'	'
Change in short-term debt and leases, net	-57,684	75,316
Dividends paid	-349,444	-156,989
Long-term notes and bonds issued	161,860	0
Redemption of bonds and notes	-164,860	0
Issuance cost of bonds and other	108	1,273
Net cash provided by (used in) financing activities	-410,020	-80,400
Net increase (decrease) in cash and cash equivalents	-121,667	-14,917
Cash and cash equivalents at beginning of period	135,530	31,010
Cash and cash equivalents at end of period	13,863	16,093
Supplemental cash flow information:	'	'
Cash payments for interest (net of capitalized interest)	180,938	159,950
Cash payments (refunds) for income taxes	($4,500)	($1,898)

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of Significant Accounting Policies	'
	The Company revised its Consolidated Statement of Cash Flows due to an immaterial error. Revisions were made in the second quarter ended June 30, 2013 on the Company's Consolidated Statement of Cash Flows to reflect energy efficiency expenditures as operating cash outflows instead of investing cash outflows. The Company determined energy efficiency expenditures should have been classified as operating activities instead of investing activities. These revisions decreased net cash provided by operating activities and decreased net cash used by investing activities. The revision does not affect the net change in cash and cash equivalents for any of the periods, and has no effect on the Company's Consolidated Statements of Income, Consolidated Statements of Comprehensive Income, Consolidated Balance Sheets, and Consolidated Statement of Common Shareholder's Equity. The Company has evaluated the effects of these errors and concluded that none of them are material to any of the Company's previously issued quarterly or annual Financial Statements. Nevertheless, the Company has elected to revise the Consolidated Statement of Cash Flows in this report to correct for the effect of these errors and properly reflect the revised values.
	The amounts on prior period Consolidated Statements of Cash Flows that have been revised are summarized below:
					As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	30,232		$	26,198		$	(28,953	)	$	(170,374	)	$	(64,173	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	323,807		$	888,691		$	1,010,328		$	865,949		$	301,265		$	782,685		$	915,923		$	770,223
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,362	)	$	(798,976	)	$	(1,076,815	)	$	(905,767	)	$	(63,820	)	$	(692,970	)	$	(982,410	)	$	(810,041	)
					As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	29,271		$	26,198		$	(28,953	)	$	(170,374	)	$	(65,134	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	332,243		$	903,888		$	903,422		$	575,775		$	309,701		$	797,882		$	809,017		$	480,049
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,298	)	$	(778,075	)	$	(1,060,588	)	$	(905,767	)	$	(63,756	)	$	(672,069	)	$	(966,183	)	$	(810,041	)
		As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	$	(110,088	)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	273,604		$	545,857		$	696,242		$	250,947		$	497,625		$	626,139
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(225,955	)	$	(474,903	)	$	(673,248	)	$	(203,298	)	$	(426,671	)	$	(603,145	)
		As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	(110,088		)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	261,229		$	566,429		$	717,894		$	238,572		$	518,197		$	647,791
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(211,766	)	$	(454,128	)	$	(652,411	)	$	(189,109	)	$	(405,896	)	$	(582,308	)

New_Accounting_Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
New Accounting Pronouncements	'
	New Accounting Pronouncements
	Balance Sheet
	In December 2011, the Financial Accounting Standards Board (FASB) issued ASU 2011-11, Balance Sheet (Topic 210) (ASU 2011-11). ASU 2011-11, as amended by ASU 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, enhances disclosure requirements about the nature of an entity's right to offset and related arrangements associated with its derivative instruments. ASU 2011-11 requires the disclosure of the gross amounts subject to rights of set-off, amounts offset in accordance with the accounting standards followed, and the related net exposure.
	ASU 2011-11, as amended, is effective for fiscal years, and interim periods within those years, beginning on or after January 1, 2013. Retrospective application of the disclosures is required for all periods presented within the financial statements.  These disclosure requirements are the only impact on the Company’s consolidated financial statements. The Company adopted the Accounting Standard Update (ASU) requirements as disclosed in Note 3 - Accounting for Derivative Instruments and Hedging Activities.
	Comprehensive Income
	In February 2013, the FASB issued ASU 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (ASU 2013-02), to improve the transparency of reporting reclassifications out of accumulated other comprehensive income. ASU 2013-02 requires an entity to present (either on the face of the statement where net income is presented or in the notes) the effects on the line items of net income of significant amounts reclassified out of accumulated other comprehensive income but only if the item reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. ASU 2013-02 also requires an entity to cross-reference to other disclosures currently required under U.S. GAAP for other reclassification items (that are not required under U.S. GAAP) to be reclassified directly to net income in their entirety in the same reporting period. This would be the case when a portion of the amount reclassified out of accumulated other comprehensive income is initially transferred to a balance sheet account instead of directly to income or expense.
	ASU 2013-02 is effective for reporting periods beginning after December 15, 2012, for public companies and is effective for reporting periods beginning after December 15, 2013, for private companies. Other than additional disclosures or a change in the presentation on the statement of comprehensive income when necessary, ASU 2013-02 does not impact the Company's consolidated results of operations, cash flows or financial position. The Company adopted the ASU requirements as disclosed in Note 8 - Accumulated Other Comprehensive Income (Loss).

Accounting_for_Derivative_Inst

Accounting for Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2013
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 PCA. Therefore, wholesale market transactions and 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 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 and financial agreements, floating-for-fixed swap contracts, and commodity call/put options. The forward physical electric contracts are both fixed and variable (at index) while the physical natural gas contracts are variable with investment grade counterparties that do not require collateral calls on the contracts. To fix the price of wholesale electricity and natural gas, PSE may enter into floating-for-fixed swap (financial) contracts with various counterparties. PSE also trades natural gas call and put options. Utilizing options as an additional hedging instrument increases the hedging portfolio's flexibility to react to commodity price fluctuations, as well as creates a commodity price cap for customers, thus protecting rate payers against future price increases.
	Due to the merger in 2009, Puget Energy recorded all derivative contracts at fair value as either assets or liabilities. Certain contracts meeting the criteria defined in ASC 815 were subsequently designated as Normal Purchase Normal Sale (NPNS) or cash flow hedges, thereby causing differences in the derivative unrealized gains/losses to be recorded through earnings between Puget Energy and PSE. These differences will occur through March 2015.
	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. As of September 30, 2013, Puget Energy had two interest rate swap contracts outstanding which extend to January 2017. PSE did not have any outstanding interest rate swap instruments.
	The following table presents the volumes, fair values and locations of the Company's derivative instruments recorded on the balance sheets:
	Puget Energy and Puget Sound Energy	September 30, 2013							December 31, 2012
	(Dollars in Thousands)	Volumes	Assets 1			Liabilities 2			Volumes	Assets 1			Liabilities 2
	Interest rate swap derivatives 3	$450 million	$	—		$	14,722		$450 million	$	—		$	21,524
	Electric portfolio derivatives	*	7,844			72,439			*	9,557			131,193
	Natural gas derivatives (MMBtus) 4	457,313,611	5,443			70,636			516,909,006	12,126			108,078
	Total derivative contracts		$	13,287		$	157,797			$	21,683		$	260,795
	Current		$	6,643		$	102,847			$	6,869		$	177,519
	Long-term		6,644			54,950				14,814			83,276
	Total derivative contracts		$	13,287		$	157,797			$	21,683		$	260,795
	___________
	*	Electric portfolio derivatives consist of electric generation fuel of 161,231,611 One Million British Thermal Units (MMBtus) and purchased electricity of 9,891,125 Megawatt Hours (MWhs) at September 30, 2013, and 129,693,200 MMBtus and 10,722,415 MWhs at December 31, 2012.
	1	Balance sheet location: Current and Long-term Unrealized gain on derivative instruments.
	2	Balance sheet location: Current and Long-term Unrealized loss on derivative instruments.
	3	Interest rate swap contracts are only held at Puget Energy.
	4	PSE had a net derivative liability and an offsetting regulatory asset of $65.2 million at September 30, 2013 and $96.0 million at December 31, 2012 related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, “Regulated Operations” (ASC 980) due to the Purchased Gas Adjustment (PGA) mechanism.
	For further details regarding the fair value of derivative instruments, see Note 4.
	ASU 2013-01 requires disclosure of both gross and net information for recognized derivative assets and liabilities. 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, Inc. (WSPP) agreements which standardize physical power contracts in the electric industry; International Swaps and Derivatives Association (ISDA) agreements which standardize financial gas and electric contracts; and North American Energy Standards Board (NAESB) agreements which standardize physical 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 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. 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 Puget Sound Energy
	At September 30, 2013	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	$	13,287		$	—		$	13,287		$	(8,672	)	$	—	$	4,615
	Liabilities
	Energy Derivative Contracts	$	143,075		$	—		$	143,075		$	(8,672	)	$	—	$	134,403
	Interest Rate Swaps 2	$	14,722		$	—		$	14,722		$	—		$	—	$	14,722
	Puget Energy and Puget Sound Energy
	At December 31, 2012	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	$	21,683		$	—		$	21,683		$	(14,126	)	$	—	$	7,557
	Liabilities
	Energy Derivative Contracts	$	239,271		$	—		$	239,271		$	(14,126	)	$	—	$	225,145
	Interest Rate Swaps 2	$	21,524		$	—		$	21,524		$	—		$	—	$	21,524
	___________
	1	All Derivative Contract deals are executed under ISDA, NAESB and WSPP Master Netting Agreements with Right of Offset.
	2	In``terest Rate Swap Contracts are only held at Puget Energy.
	The following tables present the effect and locations of the Company's derivatives not designated as hedging instruments, recorded on the statements of income:
	Puget Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Interest rate contracts:	Other deductions	$	(470	)	$	1,512		$	1,790		$	(5,258	)
		Interest expense	(3,625		)	(7,548		)	(4,301		)	(26,812		)
	Commodity contracts:
	Electric derivatives	Unrealized gain (loss) on derivative instruments, net 1	8,888			67,442			57,203			124,641
		Electric generation fuel	(9,142		)	(26,998		)	(22,710		)	(52,972		)
		Purchased electricity	2,281			(22,249		)	(32,909		)	(107,201		)
	Total gain (loss) recognized in income on derivatives		$	(2,068	)	$	12,159		$	(927	)	$	(67,602	)
	___________
	1	The nine months ended September 30, 2012, differs from the amount stated in the statements of income as it does not include amortization related to contracts that were recorded at fair value at the time of the February 2009 merger and subsequently designated as NPNS of $2.2 million.
	Puget Sound Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Commodity contracts:
	Electric derivatives	Unrealized gain (loss) on derivative instruments, net	$	8,888		$	65,594		$	54,252		$	115,309
		Electric generation fuel	(9,142		)	(26,998		)	(22,710		)	(52,972		)
		Purchased electricity	2,281			(22,249		)	(32,909		)	(107,202		)
	Total gain (loss) recognized in income on derivatives		$	2,027		$	16,347		$	(1,367	)	$	(44,865	)
	The unrealized gain or loss on derivative contracts is reported in the statement of cash flows under the operating activities section. However, at the time of the merger in 2009, all derivative contracts at Puget Energy were assessed to identify contracts that have a “more than an insignificant” fair value. If the fair value was greater than 10% of the notional value, the contract was deemed as having a financing element. For those contracts, the cash inflows (outflows) are presented in the financing activities section of the statement of cash flows. For the nine months ending September 30, 2013 and 2012, cash outflows related to financing activities of $26.0 million and $65.9 million, respectively, were reported on the Puget Energy statement of cash flows.
	For derivative instruments previously designated as cash flow hedges (including both commodity contracts and interest rate swaps), the effective portion of the gain or loss on the derivative was recorded as a component of Other Comprehensive Income (OCI), and then is reclassified into earnings in the same period(s) during which the hedged transaction affects earnings. During the quarter ending September 30, 2013, Puget Energy paid down $80.0 million of the amount outstanding under its revolving senior secured credit facility, bringing the balance down to $299.0 million. As the related forecasted transactions (i.e. future interest payments associated with the debt pay down) are now remote of occurring, Puget Energy reclassified a $0.5 million loss from accumulated OCI into earnings.
	Puget Energy and PSE expect $1.5 million and $2.2 million of losses, respectively, in accumulated OCI will be reclassified into earnings within the next twelve months. The Company does not use cash flow hedging for any new transactions and records all mark-to-market adjustments through earnings.
The following tables present the Company's pre-tax gain (loss) of derivatives that were in a previous cash flow hedge relationship, reclassified out of accumulated OCI into income:
Puget Energy		Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in Thousands)	Location	2013			2012			2013			2012
Interest rate contracts:	Interest expense	$	(1,247	)	$	(1,623	)	$	(3,886	)	$	(16,386	)
Commodity contracts:
Electric derivatives	Electric generation fuel	—			—			—			100
	Purchased electricity	—			(392		)	164			(380		)
Total		$	(1,247	)	$	(2,015	)	$	(3,722	)	$	(16,666	)
Puget Sound Energy		Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in Thousands)	Location	2013			2012			2013			2012
Interest rate contracts:	Interest expense	$	(122	)	$	(122	)	$	(366	)	$	(366	)
Commodity contracts:
Electric derivatives	Electric generation fuel	—			—			—			97
	Purchased electricity	—			(2,240		)	(2,786		)	(9,708		)
Total		$	(122	)	$	(2,362	)	$	(3,152	)	$	(9,977	)
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, exposure monitoring and exposure mitigation.
The Company monitors counterparties that have significant swings in credit default swap rates, have credit rating changes by external rating agencies, have changes in ownership or are experiencing 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, 2013, approximately 99.9% of the Company's energy portfolio exposure, excluding NPNS transactions, is with counterparties that are rated at least investment grade by the major rating agencies and 0.1% are either rated below investment grade or not rated by rating agencies. The Company assesses credit risk internally for counterparties that are not rated.
As the Company generally enters into transactions using the WSPP, ISDA and NAESB master agreements, it believes that such agreements reduce credit risk exposure because they provide for the netting and offsetting of monthly payments and, in the event of counterparty default, termination payments.
The Company computes credit reserves at a master agreement level by counterparty (i.e., WSPP, ISDA, or NAESB). The Company considers external credit ratings and market factors, such as credit default swaps and bond spreads, in the determination of reserves. 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 used 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 booked as contra accounts to unrealized gain (loss) positions. As of September 30, 2013, the Company was in a net liability position with the majority of counterparties, so the default factors of counterparties did not have a significant impact on reserves for the quarter. The majority of the Company's derivative contracts are with financial institutions and other utilities operating within the Western Electricity Coordinating Council. During the third quarter of 2013, PSE was required to post a $0.3 million letter of credit as a condition of transacting on a physical energy exchange and clearinghouse in Canada. 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.
The table below presents the fair value of the overall contractual contingent liability positions for the Company's derivative activity at September 30, 2013:
Puget Energy and Puget Sound Energy	Fair Value 1			Posted			Contingent
Contingent Feature	Liability			Collateral			Collateral
(Dollars in Thousands)
Credit rating 2	$	(37,598	)	$	—		$	37,598
Requested credit for adequate assurance	(31,358		)	—			—
Forward value of contract 3	(168		)	—			—
Total	$	(69,124	)	$	—		$	37,598
__________
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, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value
	GAAP 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 because 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 market from an independent external pricing service. For interest rate swaps, the Company obtains monthly mark-to-market values from an independent external pricing service for London Interbank Offered Rate (LIBOR) forward rates, which is a significant input. Some of the inputs of the interest rate swap valuations, which are not significant, include the credit standing of the counterparties, assumptions for time value and the impact of the Company's nonperformance risk of its liabilities. Cash equivalents and restricted cash classified as Level 2 fair value instruments consist of special money market funds and premium checking accounts. The Company valued Level 2 cash equivalents and restricted cash using the market approach based on the fair value of underlying investments at reporting date.
	The Company considers its electric, natural gas and interest rate swap contracts as Level 2 derivative instruments as such contracts are commonly traded as over-the-counter forwards with indirectly observable price quotes. Management's assessment was 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 (e.g., Level 2 in the fair value hierarchy) used to value commodity contracts with the actual prices of commodity contracts entered into during the most recent quarter. However, certain energy derivative instruments with maturity dates falling outside the range of observable price quotes are classified as Level 3 in the fair value hierarchy.
	Assets and Liabilities with Estimated Fair Value
	The following table presents the fair value hierarchy by level, the carrying value for cash, cash equivalents, restricted cash, notes receivable and short-term debt. The carrying values below are representative of fair values due to the short-term nature of these financial instruments.
		Carrying / Fair Value									Carrying / Fair Value
	Puget Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 1			Level 2			Total			Level 1			Level 2			Total
	Assets:
	Cash and Cash Equivalents	$	—		$	14,033		$	14,033		$	105,000		$	30,542		$	135,542
	Restricted Cash	5,305			2,460			7,765			914			2,786			3,700
	Notes Receivable and Other	—			52,844			52,844			—			63,802			63,802
	Total assets	$	5,305		$	69,337		$	74,642		$	105,914		$	97,130		$	203,044
	Liabilities:
	Short Term Debt	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
	Total liabilities	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
		Carrying / Fair Value									Carrying / Fair Value
	Puget Sound Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 1			Level 2			Total			Level 1			Level 2			Total
	Assets:
	Cash and Cash Equivalents	$	—		$	13,863		$	13,863		$	105,000		$	30,530		$	135,530
	Restricted Cash	5,305			2,460			7,765			914			2,786			3,700
	Notes Receivable and Other	—			52,844			52,844			—			63,802			63,802
	Total assets	$	5,305		$	69,167		$	74,472		$	105,914		$	97,118		$	203,032
	Liabilities:
	Short Term Debt	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
	Short Term Debt owed to parent	—			29,598			29,598			—			29,598			29,598
	Total liabilities	$	129,000		$	29,598		$	158,598		$	181,000		$	29,598		$	210,598
	The fair value of the junior subordinated and long-term notes were estimated using the discounted cash flow method with U.S. Treasury yields and Company credit spreads as inputs, interpolating to the maturity date of each issue. Carrying values and estimated fair values were as follows:
	Puget Energy		September 30, 2013						December 31, 2012
	(Dollars in Thousands)	Level	Carrying			Fair			Carrying			Fair
			Value			Value			Value			Value
	Liabilities:
	Junior subordinated notes	2	$	250,000		$	258,389		$	250,000		$	264,842
	Long-term debt (fixed-rate), net of discount	2	4,690,693			5,665,300			4,662,200			6,197,179
	Long-term debt (variable-rate), net of discount	2	299,000			299,000			434,000			434,000
	Total		$	5,239,693		$	6,222,689		$	5,346,200		$	6,896,021
	Puget Sound Energy		September 30, 2013						December 31, 2012
	(Dollars in Thousands)	Level	Carrying			Fair			Carrying			Fair
			Value			Value			Value			Value
	Liabilities:
	Junior subordinated notes	2	$	250,000		$	258,389		$	250,000		$	264,842
	Long-term debt (fixed-rate), net of discount	2	3,523,258			4,144,357			3,526,258			4,628,509
	Total		$	3,773,258		$	4,402,746		$	3,776,258		$	4,893,351
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The following tables present 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 and the reconciliation of the changes in the fair value of Level 3 derivatives in the fair value hierarchy. The Company did not have any transfers between Level 2 and Level 1 during the three and nine months ended September 30, 2013 and 2012.
	Puget Energy	Fair Value									Fair Value
		At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 2			Level 3			Total			Level 2			Level 3			Total
	Interest rate derivative instruments	$	14,722		$	—		$	14,722		$	21,524		$	—		$	21,524
	Total derivative liabilities	$	14,722		$	—		$	14,722		$	21,524		$	—		$	21,524
	Puget Energy and	Fair Value									Fair Value
	Puget Sound Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 2			Level 3			Total			Level 2			Level 3			Total
	Assets:
	Electric derivative instruments	$	2,223		$	5,621		$	7,844		$	1,259		$	8,298		$	9,557
	Natural gas derivative instruments	2,100			3,343			5,443			6,769			5,357			12,126
	Total assets	$	4,323		$	8,964		$	13,287		$	8,028		$	13,655		$	21,683
	Liabilities:
Electric derivative instruments	$	37,699		$	34,740		$	72,439		$	88,971		$	42,221		$	131,192
Natural gas derivative instruments	64,494			6,142			70,636			101,119			6,960			108,079
Total liabilities	$	102,193		$	40,882		$	143,075		$	190,090		$	49,181		$	239,271
Puget Energy and	Three Months Ended September 30,
Puget Sound Energy
Level 3 Roll-Forward Net (Liability)	2013									2012
(Dollars in Thousands)	Electric			Gas			Total			Electric			Gas			Total
Balance at beginning of period	$	(36,899	)	$	(2,873	)	$	(39,772	)	$	(80,453	)	$	(2,819	)	$	(83,272	)
Changes during period:
Realized and unrealized energy derivatives:
Included in earnings 1	(392		)	—			(392		)	5,332			—			5,332
Included in regulatory assets / liabilities	—			(957		)	(957		)	—			(183		)	(183		)
Settlements 3	(1,270		)	466			(804		)	11,606			1,102			12,708
Transferred into Level 3	730			—			730			—			—			—
Transferred out of Level 3	8,712			565			9,277			11,831			471			12,302
Balance at end of period	$	(29,119	)	$	(2,799	)	$	(31,918	)	$	(51,684	)	$	(1,429	)	$	(53,113	)
Puget Energy and	Nine Months Ended
Puget Sound Energy	September 30,
Level 3 Roll-Forward Net (Liability)	2013									2012
(Dollars in Thousands)	Electric			Gas			Total			Electric			Gas			Total
Balance at beginning of period	$	(33,924	)	$	(1,602	)	$	(35,526	)	$	(90,311	)	$	(5,041	)	$	(95,352	)
Changes during period:
Realized and unrealized energy derivatives:
Included in earnings 2	(11,593		)	—			(11,593		)	(11,538		)	—			(11,538		)
Included in regulatory assets / liabilities	—			(967		)	(967		)	—			(1,470		)	(1,470		)
Settlements 3	7,792			(762		)	7,030			47,021			1,208			48,229
Transferred into Level 3	(7,799		)	—			(7,799		)	(55,548		)	(297		)	(55,845		)
Transferred out of Level 3	16,405			532			16,937			58,692			4,171			62,863
Balance at end of period	$	(29,119	)	$	(2,799	)	$	(31,918	)	$	(51,684	)	$	(1,429	)	$	(53,113	)
_________
1	Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(0.8) million and $5.1 million for the three months ended September 30, 2013 and 2012, respectively.
2	Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(15.0) million and $(7.6) million for the nine months ended September 30, 2013 and 2012, respectively.
3 The Company had no purchases, sales or issuances during the reported periods.
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.
In order to determine which assets and liabilities are classified as Level 3, the Company receives market data from its independent external pricing service defining the tenor of observable market quotes. To the extent any of the Company's commodity contracts extend beyond what is considered observable as defined by its independent pricing service, the contracts are classified as Level 3. The actual tenor of what the independent pricing service defines as observable is subject to change depending on market conditions. Therefore, as the market changes, the same contract may be designated Level 3 one month and Level 2 the next, and vice versa. The changes of fair value classification into or out of Level 3 are recognized each month, and reported in the Level 3 Roll-forward table above. The Company does periodically transact at locations, or market price points, that are illiquid or for which no prices are available from the independent pricing service. In such circumstances the Company uses a more liquid price point and performs a 15-month regression against the illiquid locations to serve as a proxy for market prices. Such transactions are classified as Level 3. 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. Below are the forward price ranges for the Company's purchased commodity contracts, as of September 30, 2013:
(Dollars in Thousands)
	Fair Value								Range
Derivative Instrument	Assets 1			Liabilities 1			Valuation Technique	Unobservable Input	Low	High	Weighted Average
Electric	$	5,621		$	34,740		Discounted cash flow	Power Prices	$12.49 per MWh	$42.80 per MWh	$31.03 per MWh
Natural gas	$	3,343		$	6,142		Discounted cash flow	Natural Gas Prices	$3.53 per MMBtu	$4.54 per MMBtu	$4.15 per MMBtu
__________
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. At September 30, 2013, 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 $16.2 million.
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
At the time of merger, Puget Energy recorded 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 nonperformance 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 impairment on an annual basis, and upon the occurrence of any events or circumstances that would be more likely than not to reduce the fair value of the long-lived assets below their carrying value. One such triggering event is a significant decrease in market price.
At June 30, 2013, Puget Energy completed a valuation and impairment test of its purchased power contracts classified as intangible assets. The valuation indicated a fair value of $484.1 million with an impairment to one of the purchased power contracts. As of June 30, 2013, the carrying value for the Priest Rapids Reasonable Portion intangible asset contract was $47.1 million and its fair value on a discounted basis was determined to be an asset of $33.6 million, thereby requiring a write-down of $13.5 million to the intangible asset with a corresponding reduction in the regulatory liability.
The valuation was measured using the income approach. Significant inputs included forward electricity prices and power contract pricing which provided future net cash flow estimates which are classified as Level 3 within the fair value hierarchy. An insignificant input is the discount rate reflective of PSE's cost of capital used in the valuation. Below are significant unobservable inputs used estimating the long-term power purchase contracts' fair value of $484.1 million on June 30, 2013:
Valuation Technique	Unobservable Input	Low			High			Weighted Average
Discounted cash flow	Power prices	$	30.85	per MWh	$	65.35	per MWh	$	48.47	per MWh
Discounted cash flow	Power contract costs (in thousands)	$	389	per year	$	6,845	per year	$	4,110	per year

Retirement_Benefits

Retirement Benefits	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Retirement Benefits	'
		Retirement Benefits
	PSE has a defined benefit pension plan covering substantially all PSE employees.  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.  PSE also maintains a non-qualified Supplemental Executive Retirement Plan (SERP) for its key senior management employees.  In addition to providing pension benefits, PSE provides group health care and life insurance benefits for certain retired employees.  These benefits are provided principally through an insurance company.  The insurance premiums, paid primarily by retirees, are based on the benefits provided during the year.
	The 2009 merger of Puget Energy with Puget Holdings triggered a new basis of accounting for PSE’s retirement benefit plans in the Puget Energy consolidated financial statements.  Such purchase accounting adjustments associated with the remeasurement of the retirement plans are recorded at Puget Energy.
	The following tables summarize the Company’s net periodic benefit cost for the three and nine months ended September 30, 2013 and 2012:
	Puget Energy
	Three Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	4,822		$	4,232		$	375		$	268		$	34		$	35
	Interest cost	6,188			6,496			511			538			166			188
	Expected return on plan assets	(9,774		)	(9,051		)	—			—			(109		)	(109		)
	Amortization of prior service	(495		)	(495		)	(4		)	—			—			—
	cost
	Amortization of net loss	722			192			365			176			17			13
	(gain)
	Net periodic benefit cost	$	1,463		$	1,374		$	1,247		$	982		$	108		$	127
	Puget Energy
	Nine Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	14,464		$	12,695		$	1,123		$	805		$	100		$	105
	Interest cost	18,565			19,490			1,534			1,614			498			563
	Expected return on plan assets	(29,321		)	(27,153		)	—			—			(327		)	(327		)
	Amortization of prior service	(1,485		)	(1,485		)	(13		)	—			—			—
	cost
	Amortization of net loss	2,167			576			1,096			527			52			40
	(gain)
	Net periodic benefit cost	$	4,390		$	4,123		$	3,740		$	2,946		$	323		$	381
	Puget Sound Energy
	Three Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	4,822		$	4,232		$	375		$	268		$	34		$	35
	Interest cost	6,188			6,496			511			538			166			188
	Expected return on plan assets	(10,172		)	(10,384		)	—			—			(109		)	(109		)
	Amortization of prior service	(393		)	(393		)	(4		)	74			7			9
	cost
	Amortization of net loss	5,153			3,754			548			358			(71		)	(61		)
	(gain)
	Amortization of transition	—			—			—			—			—			12
	obligation
	Net periodic benefit cost	$	5,598		$	3,705		$	1,430		$	1,238		$	27		$	74
	Puget Sound Energy
	Nine Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	14,464		$	12,695		$	1,123		$	805		$	100		$	105
	Interest cost	18,565			19,490			1,534			1,614			498			563
	Expected return on plan assets	(30,514		)	(31,150		)	—			—			(327		)	(327		)
	Amortization of prior service	(1,180		)	(1,180		)	(13		)	220			22			27
	cost
	Amortization of net loss	15,459			11,261			1,645			1,074			(213		)	(184		)
	(gain)
	Amortization of transition	—			—			—			—			—			37
	obligation
	Net periodic benefit cost	$	16,794		$	11,116		$	4,289		$	3,713		$	80		$	221
	The following table summarizes the Company’s change in benefit obligation for the periods ended September 30, 2013 and December 31, 2012:
	Puget Energy and	Qualified						SERP						Other
	Puget Sound Energy	Pension Benefits						Pension Benefits						Benefits
	Nine Months Ended			Year			Nine Months Ended			Year			Nine Months Ended			Year
				Ended						Ended						Ended
(Dollars in Thousands)	September 30,			December 31,			September 30,			December 31,			September 30,			December 31,
	2013			2012			2013			2012			2013			2012
Change in benefit obligation:
Benefit obligation at beginning of period	$	616,290		$	565,997		$	51,795		$	48,370		$	17,672		$	16,436
Service cost	14,464			16,926			1,123			1,073			100			139
Interest cost	18,565			25,986			1,534			2,152			498			751
Amendment	—			—			—			(122		)	—			—
Actuarial loss/(gain)	3,436			40,914			—			5,483			(1,055		)	1,199
Benefits paid	(34,875		)	(33,533		)	(5,061		)	(5,161		)	(1,202		)	(1,523		)
Medicare part D subsidiary	—			—			—			—			125			670
received
Benefit obligation at end of period	$	617,880		$	616,290		$	49,391		$	51,795		$	16,138		$	17,672
The fair value of the Company’s qualified pension plan assets was $585.1 million and $531.2 million at September 30, 2013 and December 31, 2012, respectively.
The aggregate expected contributions by the Company to fund the qualified pension plan, SERP and the other postretirement plans for the year ending December 31, 2013 are expected to be at least $20.4 million, $5.0 million and $0.8 million, respectively. During the three months ended September 30, 2013, the Company contributed $5.1 million, $1.9 million, and $0.1 million to fund the qualified pension plan, SERP and the other postretirement plan, respectively. During the nine months ended September 30, 2013, the Company contributed $15.3 million, $5.1 million and $0.8 million to fund the qualified pension plan, SERP and the other postretirement plan, respectively.

Regulation_and_Rates

Regulation and Rates	9 Months Ended
	Sep. 30, 2013
Regulation and Rates [Abstract]	'
Regulation and Rates	'
		Regulation and Rates
	On May 7, 2012, the Washington Commission issued its order in PSE's consolidated electric and natural gas general rate case filed in June 2011, approving a general rate increase for electric customers of $63.3 million or 3.2% annually, and an increase in natural gas rates of $13.4 million or 1.3% annually. The rate increases for electric and natural gas customers became effective May 14, 2012. In its order, the Washington Commission approved a weighted cost of capital of 7.8% and a capital structure that included 48.0% common equity with a return on equity of 9.8%.
	On June 1, 2012, PSE filed with the Washington Commission a petition seeking an Accounting Order authorizing PSE to change the existing natural gas conservation tracker mechanism into a rider mechanism to be consistent with the electric conservation program recovery. The accounting petition requested the ability to recover the costs associated with the Company's current gas conservation programs via transfers from amounts deferred for the overrecovery of commodity costs in the Company's PGA mechanism. The Washington Commission granted PSE's accounting petition on June 28, 2012. The approved accounting petition resulted in an increase to gas conservation revenues of $6.9 million and an increase to conservation amortization expense of $6.6 million, the difference being recognized as revenue sensitive taxes.
	On October 31, 2012, the Washington Commission approved PSE's PGA natural gas tariff filing and allowed the rates to go into effect on November 1, 2012 on a temporary basis subject to revision. The rates resulted in a decrease to the rates charged to customers under the PGA. On May 1, 2013, the Washington Commission approved the proposed rates and allowed them to be made permanent. The estimated revenue impact of the approved change is a decrease of $77.0 million, or 7.7% annually. The rate adjustment has no impact on PSE's net income.
	On January 31, 2013, the Washington Commission approved a rate change to PSE's Federal Incentive Tracker tariff, effective February 1, 2013, which incorporated the effects of the Treasury Grant related to the Lower Snake River wind generation project and keeping the ten year amortization period and inclusion of interest on the unamortized balance of the grants. The rate change will pass through 11 months of amortization for both grants to eligible customers over 11 months beginning February 1, 2013, including grant amortization pass-back of $34.6 million and interest pass-back of $23.8 million. This represents an overall average rate decrease of 2.76%.
	On June 25, 2013, the Washington Commission approved PSE's electric and natural gas decoupling mechanism and expedited rate filing (ERF) tariff filings, effective July 1, 2013. The estimated revenue impact of the decoupling mechanism is an increase for electric of $21.4 million, or 1.0% annually, and an increase for natural gas of $10.8 million, or 1.1% annually. The estimated revenue impact of the ERF filings is an increase for electric of $30.7 million, or 1.5% annually, while the revenue impact for natural gas is a decrease of $2.0 million, or a decrease of 0.2% annually. In its order, the Washington Commission approved a weighted cost of capital of 7.77% and a capital structure that included 48.0% common equity with a return on equity of 9.8%.
	On July 24, 2013, the Public Counsel Division of the Washington State Attorney General's Office (Public Counsel) and the Industrial Customers of Northwest Utilities (ICNU) each filed a petition in Thurston County Superior Court (the Court) seeking judicial review of various aspects of the Washington Commission's ERF and decoupling mechanism final order. The parties' petition argues that the order violates various procedural and substantive requirements of the Washington Administrative Procedure Act, and so requests that it be vacated and that the matter be remanded to the Washington Commission. Oral arguments regarding this matter are scheduled for May 2014. PSE filed a motion to intervene in the proceedings, which the Court granted.  The Washington Commission filed a motion to dismiss the petitions, which will be heard by the Court on November 8, 2013.
	On April 25, 2013, PSE filed revised tariffs seeking to update its Schedule 95 rates for a power cost only rate case (PCORC) to reflect decreases in the Company's overall normalized power supply costs. PSE's initial filing represented a revenue decrease of $0.6 million (an average decrease of approximately 0.03%) for customers. PSE's rebuttal case, filed on August 28, 2013, supported a revenue decrease of $1.0 million (an average decrease of approximately 0.05%) for customers. PSE and all parties to the PCORC filed a settlement agreement supported by joint testimony with the Washington Commission on September 16, 2013. The agreement was intended to settle all issues in the proceeding and called for a revenue decrease of $10.5 million (an average decrease of approximately 0.5%) for customers. This was approved by the Washington Commission on October 23, 2013 and became effective on November 1, 2013.
	On September 24, 2013, PSE filed a Purchased Gas Adjustment (PGA) natural gas tariff with the Washington Commission which proposed to reflect changes in wholesale gas and pipeline transportation costs and changes in deferral amortization rates.  The impact of PGA rates is an annual revenue increase of $4.1 million, or 0.4%, with no impact on net operating income.  This was approved by the Washington Commission on October 30, 2013 and became effective on November 1, 2013.

Litigation

Litigation	9 Months Ended
	Sep. 30, 2013
Litigation Disclosure [Abstract]	'
Litigation	'
	Litigation
	Residential Exchange
	The Northwest Power Act, through the Residential Exchange Program (REP), provides access to the benefits of low-cost federal power for residential and small farm customers of regional utilities, including PSE.  The program is administered by the Bonneville Power Administration (BPA).  Pursuant to agreements (including settlement agreements) between the BPA and PSE, the BPA has provided payments of REP benefits to PSE, which PSE has passed through to its residential and small farm customers in the form of electricity bill credits.
	In 2007, the United States Court of Appeals for the Ninth Circuit (Ninth Circuit) ruled that REP agreements of the BPA with PSE and a number of other investor-owned utilities were inconsistent with the Northwest Power Act.  Since that time, those investor-owned utilities, including PSE, the BPA and other parties have been involved in ongoing litigation at the Ninth Circuit relating to the amount of REP benefits paid to utilities, including PSE, for the fiscal year 2002 through fiscal year 2011 period and the amount of REP benefits to be paid going forward.
	In July 2011, the BPA, PSE and a number of other parties entered into a settlement agreement that by its terms, if upheld in its entirety, would resolve the disputes between BPA and PSE regarding REP benefits paid for fiscal years 2002-2011 and determine REP benefits for fiscal years 2012-2028.  In October 2011, certain other parties challenged BPA decisions with regard to its entering into this most recent settlement agreement.   On October 28, 2013, the Ninth Circuit issued an order dismissing this challenge to this settlement; the challenging parties may seek judicial review of this Ninth Circuit opinion. Pending disposition of this challenge, the other pending Ninth Circuit litigation regarding REP benefits has been stayed by the Ninth Circuit.
	Due to the pending and ongoing proceedings, PSE is unable to reasonably estimate any amounts of REP payments either to be recovered by the BPA or to be paid for any future periods to PSE, and is unable to determine the impact, if any, these proceedings and litigation may have on PSE.  However, the Company believes it is unlikely that any unfavorable outcome would have a material adverse effect on PSE because REP benefits received by PSE are passed through to PSE's residential and small farm customers.
	Colstrip
	PSE has a 50% ownership interest in Colstrip Units 1 and 2, and a 25% interest in Colstrip Units 3 and 4. On March 6, 2013, Sierra Club and Montana Environmental Information Center (MEIC) filed a Clean Air Act citizen suit against all Colstrip owners (including PSE) alleging 39 claims for relief, most which relate to alleged prevention of significant deterioration (PSD) violations. One claim relates to the alleged failure to update the Title V permit to reflect the major modifications alleged in the first thirty-six claims, another claim alleges that the previous Title V compliance certifications have been incomplete because they did not address the alleged major modifications, and the last claim alleges opacity violations since 2007. The lawsuit was filed in U.S. District of Montana, Billings Division requesting injunctive relief and civil penalties, including a request that the owners remediate environmental damage and that $100,000 of the civil penalties be used for beneficial mitigation projects. This lawsuit followed various Notices of Intent to Sue sent to Colstrip owners (including PSE) from the Sierra Club and the MEIC between July and December 2012.  Discovery in the case has begun, and a prehearing conference took place in July 2013. The case has been bifurcated into separate liability and remedy trials set for October 2014 and August 2015, respectively. PSE is evaluating the allegations set forth in the notices and cannot at this time predict the outcome of this matter.
	Other Proceedings
	The Company is also involved in litigation relating to claims arising out of its operations in the normal course of business. The Company has recorded reserves of $1.4 million and $3.4 million relating to these claims as of September 30, 2013 and December 31, 2012, respectively.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Notes)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	The following tables present the changes in the Company’s accumulated other comprehensive income (loss) (AOCI) by component for the three and nine months ended September 30, 2013:
	Puget Energy	Net unrealized gain (loss) on interest rate swaps			Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments
	Changes in AOCI, net of tax
	(Dollars in Thousands)										Total
	Balance at June 30, 2013	$	(1,307	)	$	(29,825	)	$	(849	)	$	(31,981	)
	Other comprehensive income (loss) before reclassifications	—			—			—			—
	Amounts reclassified from accumulated other comprehensive income (loss), net of tax	811			393			—			1,204
	Net current-period other comprehensive income (loss)	811			393			—			1,204
	Balance at September 30, 2013	$	(496	)	$	(29,432	)	$	(849	)	$	(30,777	)
	Puget Energy	Net unrealized gain (loss) on interest rate swaps			Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments
	Changes in AOCI, net of tax
	(Dollars in Thousands)										Total
	Balance at December 31, 2012	$	(3,022	)	$	(29,065	)	$	(742	)	$	(32,829	)
	Other comprehensive income (loss) before reclassifications	—			(1,548		)	—			(1,548		)
	Amounts reclassified from accumulated other comprehensive income (loss), net of tax	2,526			1,181			(107		)	3,600
	Net current-period other comprehensive income (loss)	2,526			(367		)	(107		)	2,052
	Balance at September 30, 2013	$	(496	)	$	(29,432	)	$	(849	)	$	(30,777	)
	Puget Sound Energy	Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments			Net unrealized gain (loss) on treasury interest rate swaps
	Changes in AOCI, net of tax
	(Dollars in Thousands)										Total
	Balance at June 30, 2013	$	(170,733	)	$	(2,765	)	$	(6,466	)	$	(179,964	)
	Other comprehensive income (loss) before reclassifications	—			—			—			—
	Amounts reclassified from accumulated other comprehensive income (loss), net of tax	3,406			—			79			3,485
	Net current-period other comprehensive income (loss)	3,406			—			79			3,485
	Balance at September 30, 2013	$	(167,327	)	$	(2,765	)	$	(6,387	)	$	(176,479	)
	Puget Sound Energy	Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments			Net unrealized gain (loss) on treasury interest rate swaps
	Changes in AOCI, net of tax
	(Dollars in Thousands)										Total
	Balance at December 31, 2012	$	(175,998	)	$	(4,576	)	$	(6,624	)	$	(187,198	)
	Other comprehensive income (loss) before reclassifications	(1,548		)	—			—			(1,548		)
	Amounts reclassified from accumulated other comprehensive income (loss), net of tax	10,219			1,811			237			12,267
	Net current-period other comprehensive income (loss)	8,671			1,811			237			10,719
	Balance at September 30, 2013	$	(167,327	)	$	(2,765	)	$	(6,387	)	$	(176,479	)
	Details about these reclassifications out of accumulated other comprehensive income (loss) for the three months ended September 30, 2013 are as follows:
	Puget Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
	Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
	Net unrealized gain (loss) on interest rate swaps:
	Interest rate contracts	$	(1,247	)	Interest expense
		436			Tax (expense) or benefit
		$	(811	)	Net of Tax
	Net unrealized gain (loss) and prior service cost on pension plans:
	Amortization of prior service cost	499			1
	Amortization of net gain (loss)	(1,104		)	1
		(605		)	Total before tax
		212			Tax (expense) or benefit
		$	(393	)	Net of Tax
	Net unrealized gain (loss) on energy derivative instruments:
	Commodity contracts: electric derivatives	—			Purchased electricity
		—			Tax (expense) or benefit
		$	—		Net of Tax
	Total reclassification for the period	$	(1,204	)	Net of Tax
	__________
	1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
	Puget Sound Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
	Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
	Net unrealized gain (loss) and prior service cost on pension plans:
	Amortization of prior service cost	$	390		1
	Amortization of net gain (loss)	(5,630		)	1
		(5,240		)	Total before tax
		1,834			Tax (expense) or benefit
	$	(3,406	)	Net of Tax
Net unrealized gain (loss) on energy derivative instruments:
Commodity contracts: electric derivatives	—			Purchased electricity
	—			Tax (expense) or benefit
	$	—		Net of Tax
Net unrealized gain (loss) on treasury interest rate swaps:
Interest rate contracts	(122		)	Interest expense
	43			Tax (expense) or benefit
	$	(79	)	Net of Tax
Total reclassification for the period	$	(3,485	)	Net of Tax
__________
1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
Details about these reclassifications out of accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 are as follows:
Puget Energy	Nine Months Ended
(Dollars in Thousands)	September 30, 2013
Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
Net unrealized gain (loss) on interest rate swaps:
Interest rate contracts	$	(3,886	)	Interest expense
	1,360			Tax (expense) or benefit
	$	(2,526	)	Net of Tax
Net unrealized gain (loss) and prior service cost on pension plans:
Amortization of prior service cost	1,498			1
Amortization of net gain (loss)	(3,315		)	1
	(1,817		)	Total before tax
	636			Tax (expense) or benefit
	$	(1,181	)	Net of Tax
Net unrealized gain (loss) on energy derivative instruments:
Commodity contracts: electric derivatives	164			Purchased electricity
	(57		)	Tax (expense) or benefit
	107			Net of Tax
Total reclassification for the period	$	(3,600	)	Net of Tax
__________
1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
Puget Sound Energy	Nine Months Ended
(Dollars in Thousands)	September 30, 2013
Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
Net unrealized gain (loss) and prior service cost on pension plans:
Amortization of prior service cost	$	1,171		1
Amortization of net gain (loss)	(16,891		)	1
	(15,720		)	Total before tax
	5,501			Tax (expense) or benefit
	$	(10,219	)	Net of Tax
Net unrealized gain (loss) on energy derivative instruments:
Commodity contracts: electric derivatives	(2,786		)	Purchased electricity
	976			Tax (expense) or benefit
	$	(1,810	)	Net of Tax
Net unrealized gain (loss) on treasury interest rate swaps:
Interest rate contracts	(366		)	Interest expense
	129			Tax (expense) or benefit
	$	(237	)	Net of Tax
Total reclassification for the period	$	(12,266	)	Net of Tax
__________
1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).

Other

Other	3 Months Ended
	Sep. 30, 2013
Other [Abstract]	'
Other	'
	Other
	Jefferson County Public Utility District (JPUD). PSE completed the sale of its electric infrastructure assets located in Jefferson County and the transition of electrical services in the county to JPUD on March 31, 2013. The proceeds from the sale exceeded the transferred assets' net carrying value of $46.7 million resulting in a pre-tax gain of approximately $60.0 million. In its 2010 order on the subject, the Washington Commission stated that PSE must file an accounting and ratemaking petition with the Washington Commission to determine how this gain will be allocated between customers and shareholders. As a result, the gain was deferred and recorded as a regulatory liability until the Washington Commission determines the accounting and ratemaking treatment. PSE expects to complete this filing in the fourth quarter of 2013.
	For federal income tax purposes, the Company has elected to treat the transaction as an involuntary conversion under the Internal Revenue Code which allows for deferral of the tax gain if PSE acquires qualified replacement property by December 31, 2015. Based on PSE's current construction program projection, it anticipates meeting this requirement through such purchases by that date.
	Bond Issuances. On May 23, 2013, PSE refinanced $161.9 million of its Pollution Control Revenue Refunding Bonds (the Bonds) to a lower weighted average interest rate from 5.01% to 3.91%. The Bonds will mature on March 1, 2031. On or after March 1, 2023, the Company may elect to call the bonds at a redemption price of 100% of the principal amount thereof, without premium, plus accrued interest, if any, to the redemption date. Due to the refinance of the Bonds, Puget Energy wrote off $18.0 million of fair value related to the Bonds that were redeemed to interest expense.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	'
	Summary of Significant Accounting Policies
	Basis of Presentation
	Puget Energy, Inc. (Puget Energy) is an energy services holding company that owns Puget Sound Energy, Inc. (PSE).  PSE 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.  Following the merger with Puget Holdings LLC (Puget Holdings) in 2009, Puget Energy is an indirect wholly-owned subsidiary of Puget Holdings.
	The consolidated financial statements of Puget Energy reflect the accounts of Puget Energy and its subsidiary, PSE.  PSE’s consolidated financial statements include the accounts of PSE and its subsidiaries.  Puget Energy and PSE are collectively referred to herein as “the Company.”  The consolidated financial statements are presented after elimination of intercompany transactions.  PSE’s consolidated financial statements continue to be accounted for on a historical basis and do not include any purchase accounting adjustments.
	The consolidated financial statements contained in this Form 10-Q are unaudited.  In the respective opinions of the management of Puget Energy and PSE, all adjustments necessary for a fair statement of the results for the interim periods have been reflected and were of a normal recurring nature.  These consolidated financial statements should be read in conjunction with the audited financial statements (and the Combined Notes thereto) included in the combined Puget Energy and PSE Annual Report on Form 10-K for the year ended December 31, 2012.
	The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (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.
	Certain prior year amounts have been reclassified to conform to the current year presentation.
	Revenue Recognition
	Operating utility revenue is recognized when the basis of services is rendered, which includes estimated unbilled revenue. PSE's unbilled revenue uses meter readings from its automated meter reading (AMR) system. The estimate calculates unbilled usage at the end of each month as the difference between the customer meter readings on the last day of the month and the last customer meter readings billed. The unbilled usage is then priced at published rates for each schedule to estimate the unbilled revenues by customer.
	Sales to other utilities are recognized in accordance with Accounting Standards Codification (ASC) 605, “Revenue Recognition” (ASC 605) and ASC 815, “Derivatives and Hedging” (ASC 815). Non-utility subsidiaries recognize revenue when services are performed or upon the sale of assets. Revenue from retail sales is billed based on tariff rates approved by the Washington Commission. Sales of Renewable Energy Credits (RECs) are deferred as a regulatory liability.
	PSE collected Washington State excise taxes (which are a component of general retail customer rates) and municipal taxes totaling $45.9 million and $174.3 million for the three and nine months ended September 30, 2013, respectively, and $44.0 million and $178.8 million for the three and nine months ended September 30, 2012, respectively.  The Company reports the collection of such taxes on a gross basis in operating revenue and as expense in taxes other than income taxes in the accompanying consolidated statements of income.
	Beginning July 1, 2013, PSE's electric and gas operations contain a revenue decoupling mechanism under which PSE's actual energy delivery revenues related to electric transmission and distribution, gas operations and general administrative costs are compared with authorized revenues allowed under the mechanism. Any differences are deferred to a regulatory asset for under recovery or regulatory liability for over recovery. Revenues associated with power costs under the Power Cost Adjustment (PCA) mechanism and Purchased Gas Adjustment (PGA) rates are excluded from the decoupling mechanism.
	Statements of Cash Flows
	The Company has refinancing transactions that do not result in an actual exchange of cash. For these transactions, the Company evaluates if the non-exchange of cash is for convenience purposes and if so, the Company considers the transaction as if it had constructively received and disbursed the cash and presents the transaction as gross on the financing section of the statements of cash flows.
	The Company revised its Consolidated Statement of Cash Flows due to an immaterial error. Revisions were made in the second quarter ended June 30, 2013 on the Company's Consolidated Statement of Cash Flows to reflect energy efficiency expenditures as operating cash outflows instead of investing cash outflows. The Company determined energy efficiency expenditures should have been classified as operating activities instead of investing activities. These revisions decreased net cash provided by operating activities and decreased net cash used by investing activities. The revision does not affect the net change in cash and cash equivalents for any of the periods, and has no effect on the Company's Consolidated Statements of Income, Consolidated Statements of Comprehensive Income, Consolidated Balance Sheets, and Consolidated Statement of Common Shareholder's Equity. The Company has evaluated the effects of these errors and concluded that none of them are material to any of the Company's previously issued quarterly or annual Financial Statements. Nevertheless, the Company has elected to revise the Consolidated Statement of Cash Flows in this report to correct for the effect of these errors and properly reflect the revised values.
	The amounts on prior period Consolidated Statements of Cash Flows that have been revised are summarized below:
					As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	30,232		$	26,198		$	(28,953	)	$	(170,374	)	$	(64,173	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	323,807		$	888,691		$	1,010,328		$	865,949		$	301,265		$	782,685		$	915,923		$	770,223
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,362	)	$	(798,976	)	$	(1,076,815	)	$	(905,767	)	$	(63,820	)	$	(692,970	)	$	(982,410	)	$	(810,041	)
					As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	29,271		$	26,198		$	(28,953	)	$	(170,374	)	$	(65,134	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	332,243		$	903,888		$	903,422		$	575,775		$	309,701		$	797,882		$	809,017		$	480,049
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,298	)	$	(778,075	)	$	(1,060,588	)	$	(905,767	)	$	(63,756	)	$	(672,069	)	$	(966,183	)	$	(810,041	)
		As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	$	(110,088	)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	273,604		$	545,857		$	696,242		$	250,947		$	497,625		$	626,139
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(225,955	)	$	(474,903	)	$	(673,248	)	$	(203,298	)	$	(426,671	)	$	(603,145	)
		As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	(110,088		)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	261,229		$	566,429		$	717,894		$	238,572		$	518,197		$	647,791
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(211,766	)	$	(454,128	)	$	(652,411	)	$	(189,109	)	$	(405,896	)	$	(582,308	)
Basis of Presentation	'
	Basis of Presentation
	Puget Energy, Inc. (Puget Energy) is an energy services holding company that owns Puget Sound Energy, Inc. (PSE).  PSE 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.  Following the merger with Puget Holdings LLC (Puget Holdings) in 2009, Puget Energy is an indirect wholly-owned subsidiary of Puget Holdings.
	The consolidated financial statements of Puget Energy reflect the accounts of Puget Energy and its subsidiary, PSE.  PSE’s consolidated financial statements include the accounts of PSE and its subsidiaries.  Puget Energy and PSE are collectively referred to herein as “the Company.”  The consolidated financial statements are presented after elimination of intercompany transactions.  PSE’s consolidated financial statements continue to be accounted for on a historical basis and do not include any purchase accounting adjustments.
	The consolidated financial statements contained in this Form 10-Q are unaudited.  In the respective opinions of the management of Puget Energy and PSE, all adjustments necessary for a fair statement of the results for the interim periods have been reflected and were of a normal recurring nature.  These consolidated financial statements should be read in conjunction with the audited financial statements (and the Combined Notes thereto) included in the combined Puget Energy and PSE Annual Report on Form 10-K for the year ended December 31, 2012.
	The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (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.
	Certain prior year amounts have been reclassified to conform to the current year presentation.
Revenue Recognition	'
	Revenue Recognition
	Operating utility revenue is recognized when the basis of services is rendered, which includes estimated unbilled revenue. PSE's unbilled revenue uses meter readings from its automated meter reading (AMR) system. The estimate calculates unbilled usage at the end of each month as the difference between the customer meter readings on the last day of the month and the last customer meter readings billed. The unbilled usage is then priced at published rates for each schedule to estimate the unbilled revenues by customer.
	Sales to other utilities are recognized in accordance with Accounting Standards Codification (ASC) 605, “Revenue Recognition” (ASC 605) and ASC 815, “Derivatives and Hedging” (ASC 815). Non-utility subsidiaries recognize revenue when services are performed or upon the sale of assets. Revenue from retail sales is billed based on tariff rates approved by the Washington Commission. Sales of Renewable Energy Credits (RECs) are deferred as a regulatory liability.
	PSE collected Washington State excise taxes (which are a component of general retail customer rates) and municipal taxes totaling $45.9 million and $174.3 million for the three and nine months ended September 30, 2013, respectively, and $44.0 million and $178.8 million for the three and nine months ended September 30, 2012, respectively.  The Company reports the collection of such taxes on a gross basis in operating revenue and as expense in taxes other than income taxes in the accompanying consolidated statements of income.
	Beginning July 1, 2013, PSE's electric and gas operations contain a revenue decoupling mechanism under which PSE's actual energy delivery revenues related to electric transmission and distribution, gas operations and general administrative costs are compared with authorized revenues allowed under the mechanism. Any differences are deferred to a regulatory asset for under recovery or regulatory liability for over recovery. Revenues associated with power costs under the Power Cost Adjustment (PCA) mechanism and Purchased Gas Adjustment (PGA) rates are excluded from the decoupling mechanism.
Statements of Cash Flows	'
	Statements of Cash Flows
	The Company has refinancing transactions that do not result in an actual exchange of cash. For these transactions, the Company evaluates if the non-exchange of cash is for convenience purposes and if so, the Company considers the transaction as if it had constructively received and disbursed the cash and presents the transaction as gross on the financing section of the statements of cash flows.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2013
Entity Information [Line Items]	'
Reclassification, Policy [Policy Text Block]	'
	The Company revised its Consolidated Statement of Cash Flows due to an immaterial error. Revisions were made in the second quarter ended June 30, 2013 on the Company's Consolidated Statement of Cash Flows to reflect energy efficiency expenditures as operating cash outflows instead of investing cash outflows. The Company determined energy efficiency expenditures should have been classified as operating activities instead of investing activities. These revisions decreased net cash provided by operating activities and decreased net cash used by investing activities. The revision does not affect the net change in cash and cash equivalents for any of the periods, and has no effect on the Company's Consolidated Statements of Income, Consolidated Statements of Comprehensive Income, Consolidated Balance Sheets, and Consolidated Statement of Common Shareholder's Equity. The Company has evaluated the effects of these errors and concluded that none of them are material to any of the Company's previously issued quarterly or annual Financial Statements. Nevertheless, the Company has elected to revise the Consolidated Statement of Cash Flows in this report to correct for the effect of these errors and properly reflect the revised values.
	The amounts on prior period Consolidated Statements of Cash Flows that have been revised are summarized below:
					As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	30,232		$	26,198		$	(28,953	)	$	(170,374	)	$	(64,173	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	323,807		$	888,691		$	1,010,328		$	865,949		$	301,265		$	782,685		$	915,923		$	770,223
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,362	)	$	(798,976	)	$	(1,076,815	)	$	(905,767	)	$	(63,820	)	$	(692,970	)	$	(982,410	)	$	(810,041	)
					As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Year Ended December 31,									Three Months Ended March 31,			Year Ended December 31,
	(Dollars in Thousands)	2013			2012			2011			2010			2013			2012			2011			2010
	Operating Activities:
	Regulatory Assets	$	(6,411	)	$	(64,368	)	$	29,271		$	26,198		$	(28,953	)	$	(170,374	)	$	(65,134	)	$	(69,528	)
	Net Cash Provided by Operating Activities	$	332,243		$	903,888		$	903,422		$	575,775		$	309,701		$	797,882		$	809,017		$	480,049
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,542	)	$	(106,006	)	$	(94,405	)	$	(95,726	)	$	—		$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(86,298	)	$	(778,075	)	$	(1,060,588	)	$	(905,767	)	$	(63,756	)	$	(672,069	)	$	(966,183	)	$	(810,041	)
		As Reported									As Revised
	Puget Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	$	(110,088	)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	273,604		$	545,857		$	696,242		$	250,947		$	497,625		$	626,139
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(225,955	)	$	(474,903	)	$	(673,248	)	$	(203,298	)	$	(426,671	)	$	(603,145	)
		As Reported									As Revised
	Puget Sound Energy	Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended			Three Months Ended March 31,			Six Months Ended June 30,			Nine Months Ended
								September 30,									September 30,
	(Dollars in Thousands)	2012			2012			2012			2012			2012			2012
	Operating Activities:
	Regulatory Assets	$	(48,185	)	$	(61,856	)	$	(60,434	)	$	(70,842	)	(110,088		)	$	(130,537	)
	Net Cash Provided by Operating Activities	$	261,229		$	566,429		$	717,894		$	238,572		$	518,197		$	647,791
	Investing Activities:
	Energy Efficiency Expenditures	$	(22,657	)	$	(48,232	)	$	(70,103	)	$	—		$	—		$	—
	Net Cash Used in Investing Activities	$	(211,766	)	$	(454,128	)	$	(652,411	)	$	(189,109	)	$	(405,896	)	$	(582,308	)

Accounting_for_Derivative_Inst1

Accounting for Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative [Line Items]	'
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	'
	The following table presents the volumes, fair values and locations of the Company's derivative instruments recorded on the balance sheets:
	Puget Energy and Puget Sound Energy	September 30, 2013							December 31, 2012
	(Dollars in Thousands)	Volumes	Assets 1			Liabilities 2			Volumes	Assets 1			Liabilities 2
	Interest rate swap derivatives 3	$450 million	$	—		$	14,722		$450 million	$	—		$	21,524
	Electric portfolio derivatives	*	7,844			72,439			*	9,557			131,193
	Natural gas derivatives (MMBtus) 4	457,313,611	5,443			70,636			516,909,006	12,126			108,078
	Total derivative contracts		$	13,287		$	157,797			$	21,683		$	260,795
	Current		$	6,643		$	102,847			$	6,869		$	177,519
	Long-term		6,644			54,950				14,814			83,276
	Total derivative contracts		$	13,287		$	157,797			$	21,683		$	260,795
	___________
	*	Electric portfolio derivatives consist of electric generation fuel of 161,231,611 One Million British Thermal Units (MMBtus) and purchased electricity of 9,891,125 Megawatt Hours (MWhs) at September 30, 2013, and 129,693,200 MMBtus and 10,722,415 MWhs at December 31, 2012.
	1	Balance sheet location: Current and Long-term Unrealized gain on derivative instruments.
	2	Balance sheet location: Current and Long-term Unrealized loss on derivative instruments.
	3	Interest rate swap contracts are only held at Puget Energy.
	4	PSE had a net derivative liability and an offsetting regulatory asset of $65.2 million at September 30, 2013 and $96.0 million at December 31, 2012 related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, “Regulated Operations” (ASC 980) due to the Purchased Gas Adjustment (PGA) mechanism.
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 Puget Sound Energy
	At September 30, 2013	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	$	13,287		$	—		$	13,287		$	(8,672	)	$	—	$	4,615
	Liabilities
	Energy Derivative Contracts	$	143,075		$	—		$	143,075		$	(8,672	)	$	—	$	134,403
	Interest Rate Swaps 2	$	14,722		$	—		$	14,722		$	—		$	—	$	14,722
	Puget Energy and Puget Sound Energy
	At December 31, 2012	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	$	21,683		$	—		$	21,683		$	(14,126	)	$	—	$	7,557
	Liabilities
	Energy Derivative Contracts	$	239,271		$	—		$	239,271		$	(14,126	)	$	—	$	225,145
	Interest Rate Swaps 2	$	21,524		$	—		$	21,524		$	—		$	—	$	21,524
	___________
	1	All Derivative Contract deals are executed under ISDA, NAESB and WSPP Master Netting Agreements with Right of Offset.
	2	In``terest Rate Swap Contracts are only held at Puget Energy.
Schedule of Credit Risk Related Contingent Features	'
	The table below presents the fair value of the overall contractual contingent liability positions for the Company's derivative activity at September 30, 2013:
	Puget Energy and Puget Sound Energy	Fair Value 1			Posted			Contingent
	Contingent Feature	Liability			Collateral			Collateral
	(Dollars in Thousands)
	Credit rating 2	$	(37,598	)	$	—		$	37,598
	Requested credit for adequate assurance	(31,358		)	—			—
	Forward value of contract 3	(168		)	—			—
	Total	$	(69,124	)	$	—		$	37,598
	__________
	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.
PUGET ENERGY [Member]	'
Derivative [Line Items]	'
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	'
	The following tables present the effect and locations of the Company's derivatives not designated as hedging instruments, recorded on the statements of income:
	Puget Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Interest rate contracts:	Other deductions	$	(470	)	$	1,512		$	1,790		$	(5,258	)
		Interest expense	(3,625		)	(7,548		)	(4,301		)	(26,812		)
	Commodity contracts:
	Electric derivatives	Unrealized gain (loss) on derivative instruments, net 1	8,888			67,442			57,203			124,641
		Electric generation fuel	(9,142		)	(26,998		)	(22,710		)	(52,972		)
		Purchased electricity	2,281			(22,249		)	(32,909		)	(107,201		)
	Total gain (loss) recognized in income on derivatives		$	(2,068	)	$	12,159		$	(927	)	$	(67,602	)
	___________
	1	The nine months ended September 30, 2012, differs from the amount stated in the statements of income as it does not include amortization related to contracts that were recorded at fair value at the time of the February 2009 merger and subsequently designated as NPNS of $2.2 million.
Subsidiaries [Member]	'
Derivative [Line Items]	'
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	'
	Puget Sound Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Commodity contracts:
	Electric derivatives	Unrealized gain (loss) on derivative instruments, net	$	8,888		$	65,594		$	54,252		$	115,309
		Electric generation fuel	(9,142		)	(26,998		)	(22,710		)	(52,972		)
		Purchased electricity	2,281			(22,249		)	(32,909		)	(107,202		)
	Total gain (loss) recognized in income on derivatives		$	2,027		$	16,347		$	(1,367	)	$	(44,865	)
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)	'
	Puget Sound Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Interest rate contracts:	Interest expense	$	(122	)	$	(122	)	$	(366	)	$	(366	)
	Commodity contracts:
	Electric derivatives	Electric generation fuel	—			—			—			97
		Purchased electricity	—			(2,240		)	(2,786		)	(9,708		)
	Total		$	(122	)	$	(2,362	)	$	(3,152	)	$	(9,977	)
Parent [Member]	'
Derivative [Line Items]	'
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)	'
	The following tables present the Company's pre-tax gain (loss) of derivatives that were in a previous cash flow hedge relationship, reclassified out of accumulated OCI into income:
	Puget Energy		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in Thousands)	Location	2013			2012			2013			2012
	Interest rate contracts:	Interest expense	$	(1,247	)	$	(1,623	)	$	(3,886	)	$	(16,386	)
	Commodity contracts:
	Electric derivatives	Electric generation fuel	—			—			—			100
		Purchased electricity	—			(392		)	164			(380		)
	Total		$	(1,247	)	$	(2,015	)	$	(3,722	)	$	(16,666	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Fair Value, by Balance Sheet Grouping	'
	The following table presents the fair value hierarchy by level, the carrying value for cash, cash equivalents, restricted cash, notes receivable and short-term debt. The carrying values below are representative of fair values due to the short-term nature of these financial instruments.
		Carrying / Fair Value									Carrying / Fair Value
	Puget Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 1			Level 2			Total			Level 1			Level 2			Total
	Assets:
	Cash and Cash Equivalents	$	—		$	14,033		$	14,033		$	105,000		$	30,542		$	135,542
	Restricted Cash	5,305			2,460			7,765			914			2,786			3,700
	Notes Receivable and Other	—			52,844			52,844			—			63,802			63,802
	Total assets	$	5,305		$	69,337		$	74,642		$	105,914		$	97,130		$	203,044
	Liabilities:
	Short Term Debt	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
	Total liabilities	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
		Carrying / Fair Value									Carrying / Fair Value
	Puget Sound Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 1			Level 2			Total			Level 1			Level 2			Total
	Assets:
	Cash and Cash Equivalents	$	—		$	13,863		$	13,863		$	105,000		$	30,530		$	135,530
	Restricted Cash	5,305			2,460			7,765			914			2,786			3,700
	Notes Receivable and Other	—			52,844			52,844			—			63,802			63,802
	Total assets	$	5,305		$	69,167		$	74,472		$	105,914		$	97,118		$	203,032
	Liabilities:
	Short Term Debt	$	129,000		$	—		$	129,000		$	181,000		$	—		$	181,000
	Short Term Debt owed to parent	—			29,598			29,598			—			29,598			29,598
	Total liabilities	$	129,000		$	29,598		$	158,598		$	181,000		$	29,598		$	210,598
Fair Value Inputs, Liabilities, Quantitative Information	'
	The fair value of the junior subordinated and long-term notes were estimated using the discounted cash flow method with U.S. Treasury yields and Company credit spreads as inputs, interpolating to the maturity date of each issue. Carrying values and estimated fair values were as follows:
	Puget Energy		September 30, 2013						December 31, 2012
	(Dollars in Thousands)	Level	Carrying			Fair			Carrying			Fair
			Value			Value			Value			Value
	Liabilities:
	Junior subordinated notes	2	$	250,000		$	258,389		$	250,000		$	264,842
	Long-term debt (fixed-rate), net of discount	2	4,690,693			5,665,300			4,662,200			6,197,179
	Long-term debt (variable-rate), net of discount	2	299,000			299,000			434,000			434,000
	Total		$	5,239,693		$	6,222,689		$	5,346,200		$	6,896,021
	Puget Sound Energy		September 30, 2013						December 31, 2012
	(Dollars in Thousands)	Level	Carrying			Fair			Carrying			Fair
			Value			Value			Value			Value
	Liabilities:
	Junior subordinated notes	2	$	250,000		$	258,389		$	250,000		$	264,842
	Long-term debt (fixed-rate), net of discount	2	3,523,258			4,144,357			3,526,258			4,628,509
	Total		$	3,773,258		$	4,402,746		$	3,776,258		$	4,893,351
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	'
	Puget Energy and	Three Months Ended September 30,
	Puget Sound Energy
	Level 3 Roll-Forward Net (Liability)	2013									2012
	(Dollars in Thousands)	Electric			Gas			Total			Electric			Gas			Total
	Balance at beginning of period	$	(36,899	)	$	(2,873	)	$	(39,772	)	$	(80,453	)	$	(2,819	)	$	(83,272	)
	Changes during period:
	Realized and unrealized energy derivatives:
	Included in earnings 1	(392		)	—			(392		)	5,332			—			5,332
	Included in regulatory assets / liabilities	—			(957		)	(957		)	—			(183		)	(183		)
	Settlements 3	(1,270		)	466			(804		)	11,606			1,102			12,708
	Transferred into Level 3	730			—			730			—			—			—
	Transferred out of Level 3	8,712			565			9,277			11,831			471			12,302
	Balance at end of period	$	(29,119	)	$	(2,799	)	$	(31,918	)	$	(51,684	)	$	(1,429	)	$	(53,113	)
	Puget Energy and	Nine Months Ended
	Puget Sound Energy	September 30,
	Level 3 Roll-Forward Net (Liability)	2013									2012
	(Dollars in Thousands)	Electric			Gas			Total			Electric			Gas			Total
	Balance at beginning of period	$	(33,924	)	$	(1,602	)	$	(35,526	)	$	(90,311	)	$	(5,041	)	$	(95,352	)
	Changes during period:
	Realized and unrealized energy derivatives:
	Included in earnings 2	(11,593		)	—			(11,593		)	(11,538		)	—			(11,538		)
	Included in regulatory assets / liabilities	—			(967		)	(967		)	—			(1,470		)	(1,470		)
	Settlements 3	7,792			(762		)	7,030			47,021			1,208			48,229
	Transferred into Level 3	(7,799		)	—			(7,799		)	(55,548		)	(297		)	(55,845		)
	Transferred out of Level 3	16,405			532			16,937			58,692			4,171			62,863
	Balance at end of period	$	(29,119	)	$	(2,799	)	$	(31,918	)	$	(51,684	)	$	(1,429	)	$	(53,113	)
	_________
	1	Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(0.8) million and $5.1 million for the three months ended September 30, 2013 and 2012, respectively.
	2	Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(15.0) million and $(7.6) million for the nine months ended September 30, 2013 and 2012, respectively.
	3 The Company had no purchases, sales or issuances during the reported periods
Fair Value Inputs, Assets and Liabilities, Quantitative Information	'
	Below are the forward price ranges for the Company's purchased commodity contracts, as of September 30, 2013:
	(Dollars in Thousands)
		Fair Value								Range
	Derivative Instrument	Assets 1			Liabilities 1			Valuation Technique	Unobservable Input	Low	High	Weighted Average
	Electric	$	5,621		$	34,740		Discounted cash flow	Power Prices	$12.49 per MWh	$42.80 per MWh	$31.03 per MWh
	Natural gas	$	3,343		$	6,142		Discounted cash flow	Natural Gas Prices	$3.53 per MMBtu	$4.54 per MMBtu	$4.15 per MMBtu
	__________
	1	The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions
PUGET ENERGY [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The Company did not have any transfers between Level 2 and Level 1 during the three and nine months ended September 30, 2013 and 2012.
	Puget Energy	Fair Value									Fair Value
		At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 2			Level 3			Total			Level 2			Level 3			Total
	Interest rate derivative instruments	$	14,722		$	—		$	14,722		$	21,524		$	—		$	21,524
	Total derivative liabilities	$	14,722		$	—		$	14,722		$	21,524		$	—		$	21,524
Subsidiaries [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	Puget Energy and	Fair Value									Fair Value
	Puget Sound Energy	At September 30, 2013									At December 31, 2012
	(Dollars in Thousands)	Level 2			Level 3			Total			Level 2			Level 3			Total
	Assets:
	Electric derivative instruments	$	2,223		$	5,621		$	7,844		$	1,259		$	8,298		$	9,557
	Natural gas derivative instruments	2,100			3,343			5,443			6,769			5,357			12,126
	Total assets	$	4,323		$	8,964		$	13,287		$	8,028		$	13,655		$	21,683
	Liabilities:
	Electric derivative instruments	$	37,699		$	34,740		$	72,439		$	88,971		$	42,221		$	131,192
	Natural gas derivative instruments	64,494			6,142			70,636			101,119			6,960			108,079
	Total liabilities	$	102,193		$	40,882		$	143,075		$	190,090		$	49,181		$	239,271

Retirement_Benefits_Tables

Retirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Schedule of Changes in Projected Benefit Obligations	'
	The following table summarizes the Company’s change in benefit obligation for the periods ended September 30, 2013 and December 31, 2012:
	Puget Energy and	Qualified						SERP						Other
	Puget Sound Energy	Pension Benefits						Pension Benefits						Benefits
		Nine Months Ended			Year			Nine Months Ended			Year			Nine Months Ended			Year
					Ended						Ended						Ended
	(Dollars in Thousands)	September 30,			December 31,			September 30,			December 31,			September 30,			December 31,
		2013			2012			2013			2012			2013			2012
	Change in benefit obligation:
	Benefit obligation at beginning of period	$	616,290		$	565,997		$	51,795		$	48,370		$	17,672		$	16,436
	Service cost	14,464			16,926			1,123			1,073			100			139
	Interest cost	18,565			25,986			1,534			2,152			498			751
	Amendment	—			—			—			(122		)	—			—
	Actuarial loss/(gain)	3,436			40,914			—			5,483			(1,055		)	1,199
	Benefits paid	(34,875		)	(33,533		)	(5,061		)	(5,161		)	(1,202		)	(1,523		)
	Medicare part D subsidiary	—			—			—			—			125			670
	received
	Benefit obligation at end of period	$	617,880		$	616,290		$	49,391		$	51,795		$	16,138		$	17,672
PUGET ENERGY [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Schedule of Net Benefit Costs	'
	following tables summarize the Company’s net periodic benefit cost for the three and nine months ended September 30, 2013 and 2012:
	Puget Energy
	Three Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	4,822		$	4,232		$	375		$	268		$	34		$	35
	Interest cost	6,188			6,496			511			538			166			188
	Expected return on plan assets	(9,774		)	(9,051		)	—			—			(109		)	(109		)
	Amortization of prior service	(495		)	(495		)	(4		)	—			—			—
	cost
	Amortization of net loss	722			192			365			176			17			13
	(gain)
	Net periodic benefit cost	$	1,463		$	1,374		$	1,247		$	982		$	108		$	127
	Puget Energy
	Nine Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	14,464		$	12,695		$	1,123		$	805		$	100		$	105
	Interest cost	18,565			19,490			1,534			1,614			498			563
	Expected return on plan assets	(29,321		)	(27,153		)	—			—			(327		)	(327		)
	Amortization of prior service	(1,485		)	(1,485		)	(13		)	—			—			—
	cost
	Amortization of net loss	2,167			576			1,096			527			52			40
	(gain)
	Net periodic benefit cost	$	4,390		$	4,123		$	3,740		$	2,946		$	323		$	381
Subsidiaries [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'
Schedule of Net Benefit Costs	'
	Puget Sound Energy
	Three Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	4,822		$	4,232		$	375		$	268		$	34		$	35
	Interest cost	6,188			6,496			511			538			166			188
	Expected return on plan assets	(10,172		)	(10,384		)	—			—			(109		)	(109		)
	Amortization of prior service	(393		)	(393		)	(4		)	74			7			9
	cost
	Amortization of net loss	5,153			3,754			548			358			(71		)	(61		)
	(gain)
	Amortization of transition	—			—			—			—			—			12
	obligation
	Net periodic benefit cost	$	5,598		$	3,705		$	1,430		$	1,238		$	27		$	74
	Puget Sound Energy
	Nine Months Ended September 30,	Qualified						SERP						Other
		Pension Benefits						Pension Benefits						Benefits
	(Dollars in Thousands)	2013			2012			2013			2012			2013			2012
	Components of net periodic benefit cost:
	Service cost	$	14,464		$	12,695		$	1,123		$	805		$	100		$	105
	Interest cost	18,565			19,490			1,534			1,614			498			563
	Expected return on plan assets	(30,514		)	(31,150		)	—			—			(327		)	(327		)
	Amortization of prior service	(1,180		)	(1,180		)	(13		)	220			22			27
	cost
	Amortization of net loss	15,459			11,261			1,645			1,074			(213		)	(184		)
	(gain)
	Amortization of transition	—			—			—			—			—			37
	obligation
	Net periodic benefit cost	$	16,794		$	11,116		$	4,289		$	3,713		$	80		$	221

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	3 Months Ended					9 Months Ended
	Sep. 30, 2013					Sep. 30, 2013
PUGET ENERGY [Member]	'					'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'					'
Schedule of Accumulated Other Comprehensive Income (Loss)	'					'
						following tables present the changes in the Company’s accumulated other comprehensive income (loss) (AOCI) by component for the three and nine months ended September 30, 2013:
						Puget Energy	Net unrealized gain (loss) on interest rate swaps			Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments
						Changes in AOCI, net of tax
						(Dollars in Thousands)										Total
						Balance at June 30, 2013	$	(1,307	)	$	(29,825	)	$	(849	)	$	(31,981	)
						Other comprehensive income (loss) before reclassifications	—			—			—			—
						Amounts reclassified from accumulated other comprehensive income (loss), net of tax	811			393			—			1,204
						Net current-period other comprehensive income (loss)	811			393			—			1,204
						Balance at September 30, 2013	$	(496	)	$	(29,432	)	$	(849	)	$	(30,777	)
						Puget Energy	Net unrealized gain (loss) on interest rate swaps			Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments
						Changes in AOCI, net of tax
						(Dollars in Thousands)										Total
						Balance at December 31, 2012	$	(3,022	)	$	(29,065	)	$	(742	)	$	(32,829	)
						Other comprehensive income (loss) before reclassifications	—			(1,548		)	—			(1,548		)
						Amounts reclassified from accumulated other comprehensive income (loss), net of tax	2,526			1,181			(107		)	3,600
						Net current-period other comprehensive income (loss)	2,526			(367		)	(107		)	2,052
						Balance at September 30, 2013	$	(496	)	$	(29,432	)	$	(849	)	$	(30,777	)
						Puget Sound Energy	Net unrealized gain (loss) and prior service cost on pension plans			Net unrealized gain (loss) on energy derivative instruments			Net unrealized gain (loss) on treasury interest rate swaps
						Changes in AOCI, net of tax
						(Dollars in Thousands)										Total
						Balance at June 30, 2013	$	(170,733	)	$	(2,765	)	$	(6,466	)	$	(179,964	)
						Other comprehensive income (loss) before reclassifications	—			—			—			—
						Amounts reclassified from accumulated other comprehensive income (loss), net of tax	3,406			—			79			3,485
						Net current-period other comprehensive income (loss)	3,406			—			79			3,485
						Balance at September 30, 2013	$	(167,327	)	$	(2,765	)	$	(6,387	)	$	(176,479	)
Reclassification out of Accumulated Other Comprehensive Income	'					'
						ils about these reclassifications out of accumulated other comprehensive income (loss) for the nine months ended September 30, 2013 are as follows:
						Puget Energy	Nine Months Ended
						(Dollars in Thousands)	September 30, 2013
						Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
						Net unrealized gain (loss) on interest rate swaps:
						Interest rate contracts	$	(3,886	)	Interest expense
							1,360			Tax (expense) or benefit
							$	(2,526	)	Net of Tax
						Net unrealized gain (loss) and prior service cost on pension plans:
						Amortization of prior service cost	1,498			1
						Amortization of net gain (loss)	(3,315		)	1
							(1,817		)	Total before tax
							636			Tax (expense) or benefit
							$	(1,181	)	Net of Tax
						Net unrealized gain (loss) on energy derivative instruments:
						Commodity contracts: electric derivatives	164			Purchased electricity
							(57		)	Tax (expense) or benefit
							107			Net of Tax
						Total reclassification for the period	$	(3,600	)	Net of Tax
						__________
						1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
						Puget Sound Energy	Nine Months Ended
						(Dollars in Thousands)	September 30, 2013
						Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
						Net unrealized gain (loss) and prior service cost on pension plans:
						Amortization of prior service cost	$	1,171		1
						Amortization of net gain (loss)	(16,891		)	1
							(15,720		)	Total before tax
							5,501			Tax (expense) or benefit
							$	(10,219	)	Net of Tax
						Net unrealized gain (loss) on energy derivative instruments:
						Commodity contracts: electric derivatives	(2,786		)	Purchased electricity
							976			Tax (expense) or benefit
							$	(1,810	)	Net of Tax
						Net unrealized gain (loss) on treasury interest rate swaps:
						Interest rate contracts	(366		)	Interest expense
							129			Tax (expense) or benefit
							$	(237	)	Net of Tax
						Total reclassification for the period	$	(12,266	)	Net of Tax
						_
Subsidiaries [Member]	'					'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'					'
Schedule of Accumulated Other Comprehensive Income (Loss)	'					'
						D
Reclassification out of Accumulated Other Comprehensive Income	'					'
	ils about these reclassifications out of accumulated other comprehensive income (loss) for the three months ended September 30, 2013 are as follows:					________
						1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
	Puget Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
	Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
	Net unrealized gain (loss) on interest rate swaps:
	Interest rate contracts	$	(1,247	)	Interest expense
		436			Tax (expense) or benefit
		$	(811	)	Net of Tax
	Net unrealized gain (loss) and prior service cost on pension plans:
	Amortization of prior service cost	499			1
	Amortization of net gain (loss)	(1,104		)	1
		(605		)	Total before tax
		212			Tax (expense) or benefit
		$	(393	)	Net of Tax
	Net unrealized gain (loss) on energy derivative instruments:
	Commodity contracts: electric derivatives	—			Purchased electricity
		—			Tax (expense) or benefit
		$	—		Net of Tax
	Total reclassification for the period	$	(1,204	)	Net of Tax
	__________
	1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
	Puget Sound Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
	Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
	Net unrealized gain (loss) and prior service cost on pension plans:
	Amortization of prior service cost	$	390		1
	Amortization of net gain (loss)	(5,630		)	1
		(5,240		)	Total before tax
		1,834			Tax (expense) or benefit
		$	(3,406	)	Net of Tax
	Net unrealized gain (loss) on energy derivative instruments:
	Commodity contracts: electric derivatives	—			Purchased electricity
		—			Tax (expense) or benefit
		$	—		Net of Tax
	Net unrealized gain (loss) on treasury interest rate swaps:
	Interest rate contracts	(122		)	Interest expense
		43			Tax (expense) or benefit
		$	(79	)	Net of Tax
	Total reclassification for the period	$	(3,485	)	Net of Tax
	ils about these reclassifications out of accumulated other comprehensive income (loss) for the three months ended September 30, 2013 are as follows:
	Puget Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
	Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
	Net unrealized gain (loss) on interest rate swaps:
	Interest rate contracts	$	(1,247	)	Interest expense
		436			Tax (expense) or benefit
		$	(811	)	Net of Tax
	Net unrealized gain (loss) and prior service cost on pension plans:
	Amortization of prior service cost	499			1
	Amortization of net gain (loss)	(1,104		)	1
		(605		)	Total before tax
		212			Tax (expense) or benefit
		$	(393	)	Net of Tax
	Net unrealized gain (loss) on energy derivative instruments:
	Commodity contracts: electric derivatives	—			Purchased electricity
		—			Tax (expense) or benefit
		$	—		Net of Tax
	Total reclassification for the period	$	(1,204	)	Net of Tax
	__________
	1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
	Puget Sound Energy	Three Months Ended
	(Dollars in Thousands)	September 30, 2013
Details about accumulated other comprehensive income (loss) components	Amount reclassified from accumulated other comprehensive income (loss)			Affected line item in the statement where net income (loss) is presented
Net unrealized gain (loss) and prior service cost on pension plans:
Amortization of prior service cost	$	390		1
Amortization of net gain (loss)	(5,630		)	1
	(5,240		)	Total before tax
	1,834			Tax (expense) or benefit
	$	(3,406	)	Net of Tax
Net unrealized gain (loss) on energy derivative instruments:
Commodity contracts: electric derivatives	—			Purchased electricity
	—			Tax (expense) or benefit
	$	—		Net of Tax
Net unrealized gain (loss) on treasury interest rate swaps:
Interest rate contracts	(122		)	Interest expense
	43			Tax (expense) or benefit
	$	(79	)	Net of Tax
Total reclassification for the period	$	(3,485	)	Net of Tax
__________
1	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 5 for additional details).
Det

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (Subsidiaries [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	sqmi		sqmi
Subsidiaries [Member]	'	'	'	'
Schedule of Capitalization, Equity [Line Items]	'	'	'	'
Area of Service Territory (in sqmi)	6,000	'	6,000	'
Excise taxes collected	$45.90	$44	$174.30	$178.80

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Cash Flow Restatements (Details) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Regulatory Assets	($28,953)	($70,842)	($110,088)	($107,379)	($130,537)	($170,374)	($64,173)	($69,528)
Net Cash Provided by (Used in) Operating Activities	301,265	250,947	497,625	579,262	626,139	782,685	915,923	770,223
Energy Efficiency Expenditures	0	0	0	'	0	0	0	0
Net Cash Provided by (Used in) Investing Activities	-63,820	-203,298	-426,671	-351,407	-603,145	-692,970	-982,410	-810,041
Scenario, Previously Reported [Member]	'	'	'	'	'	'	'	'
Regulatory Assets	-6,411	-48,185	-61,856	'	-60,434	-64,368	30,232	26,198
Net Cash Provided by (Used in) Operating Activities	323,807	273,604	545,857	'	696,242	888,691	1,010,328	865,949
Energy Efficiency Expenditures	-22,542	-22,657	-48,232	'	-70,103	-106,006	-94,405	-95,726
Net Cash Provided by (Used in) Investing Activities	-86,362	-225,955	-474,903	'	-673,248	-798,976	-1,076,815	-905,767
Subsidiaries [Member]	'	'	'	'	'	'	'	'
Regulatory Assets	-28,953	-70,842	-110,088	-107,379	-130,537	-170,374	-65,134	-69,528
Net Cash Provided by (Used in) Operating Activities	309,701	238,572	518,197	639,253	647,791	797,882	809,017	480,049
Energy Efficiency Expenditures	0	0	0	'	0	0	0	0
Net Cash Provided by (Used in) Investing Activities	-63,756	-189,109	-405,896	-350,900	-582,308	-672,069	-966,183	-810,041
Subsidiaries [Member] | Scenario, Previously Reported [Member]	'	'	'	'	'	'	'	'
Regulatory Assets	-6,411	-48,185	-61,856	'	-60,434	-64,368	29,271	26,198
Net Cash Provided by (Used in) Operating Activities	332,243	261,229	566,429	'	717,894	903,888	903,422	575,775
Energy Efficiency Expenditures	-22,542	-22,657	-48,232	'	-70,103	-106,006	-94,405	-95,726
Net Cash Provided by (Used in) Investing Activities	($86,298)	($211,766)	($454,128)	'	($652,411)	($778,075)	($1,060,588)	($905,767)

Accounting_for_Derivative_Inst2

Accounting for Derivative Instruments and Hedging Activities Derivative Activity and Notional Amounts (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Notional Amount	$450	[1]	$450	[1]
Natural Gas Derivatives [Member] | Not Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Notional amount, Nonmonetary	457,313,611	[2]	516,909,006	[2]
Electric generation fuel [Member] | Not Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Notional amount, Nonmonetary	161,231,611		129,693,200
Purchased electricity [Member] | Not Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Notional amount, Nonmonetary	9,891,125		10,722,415
PUGET ENERGY [Member] | Interest Rate Swap [Member]	'		'
Derivative [Line Items]	'		'
Number of Interest Rate Derivatives Held	2		'
[1]	Interest rate swap contracts are only held at Puget Energy.
[2]	PSE had a net derivative liability and an offsetting regulatory asset of $65.2 million at SeptemberB 30, 2013 and $96.0 million at DecemberB 31, 2012 related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, bRegulated Operationsb (ASC 980) due to the Purchased Gas Adjustment (PGA) mechanism.

Accounting_for_Derivative_Inst3

Accounting for Derivative Instruments and Hedging Activities Derivative Assets and Liabilities (Details) (USD $)	9 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Derivative [Line Items]	'		'
Document Period End Date	30-Sep-13		'
Unrealized gain on derivative instruments	$6,643,000		$6,869,000
Assets, Long-term	6,644,000		14,814,000
Unrealized loss on derivative instruments	102,847,000		177,519,000
Unrealized loss on derivative instruments	54,950,000		83,276,000
Subsidiaries [Member]	'		'
Derivative [Line Items]	'		'
Document Period End Date	30-Sep-13		'
Unrealized gain on derivative instruments	6,643,000		6,869,000
Assets, Long-term	6,644,000		14,814,000
Unrealized loss on derivative instruments	96,245,000		170,948,000
Unrealized loss on derivative instruments	46,830,000		68,323,000
Offsetting regulatory assets	65,200,000		96,000,000
Commodity Contract [Member]	'		'
Derivative [Line Items]	'		'
Assets	13,287,000		21,683,000
Liabilities	143,075,000		239,271,000
Not Designated as Hedging Instrument [Member]	'		'
Derivative [Line Items]	'		'
Assets	13,287,000	[1]	21,683,000	[1]
Liabilities	157,797,000	[2]	260,795,000	[2]
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member]	'		'
Derivative [Line Items]	'		'
Unrealized gain on derivative instruments	6,643,000	[1]	6,869,000	[1]
Assets, Long-term	6,644,000	[1]	14,814,000	[1]
Unrealized loss on derivative instruments	102,847,000	[2]	177,519,000	[2]
Unrealized loss on derivative instruments	54,950,000	[2]	83,276,000	[2]
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Notional Amount	450,000,000	[3]	450,000,000	[3]
Assets	0	[1],[3]	0	[1],[3]
Liabilities	14,722,000	[2],[3]	21,524,000	[2],[3]
Not Designated as Hedging Instrument [Member] | Electric portfolio [Member]	'		'
Derivative [Line Items]	'		'
Assets	7,844,000	[1]	9,557,000	[1]
Liabilities	72,439,000	[2]	131,193,000	[2]
Not Designated as Hedging Instrument [Member] | Natural gas portfolio [Member]	'		'
Derivative [Line Items]	'		'
Assets	5,443,000	[1],[4]	12,126,000	[1],[4]
Liabilities	$70,636,000	[2],[4]	$108,078,000	[2],[4]
Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member]	'		'
Derivative [Line Items]	'		'
Derivative, Nonmonetary Notional Amount	457,313,611	[4]	516,909,006	[4]
[1]	Balance sheet location: Current and Long-term Unrealized gain on derivative instruments.
[2]	Balance sheet location: Current and Long-term Unrealized loss on derivative instruments.
[3]	Interest rate swap contracts are only held at Puget Energy.
[4]	PSE had a net derivative liability and an offsetting regulatory asset of $65.2 million at SeptemberB 30, 2013 and $96.0 million at DecemberB 31, 2012 related to contracts used to economically hedge the cost of physical gas purchased to serve natural gas customers. All fair value adjustments on derivatives relating to the natural gas business have been deferred in accordance with ASC 980, bRegulated Operationsb (ASC 980) due to the Purchased Gas Adjustment (PGA) mechanism.

Accounting_for_Derivative_Inst4

Accounting for Derivative Instruments and Hedging Activities Net Amount of Derivatives Reported in the Statement of Financial Position (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2013		Dec. 31, 2012
			Commodity Contract [Member]		Commodity Contract [Member]		Interest Rate Contract [Member]		Interest Rate Contract [Member]
Derivative [Line Items]	'	'	'		'		'		'
Derivative contracts classified as financing activities due to merger	($25,976)	($65,906)	'		'		'		'
Assets	'	'	'		'		'		'
Gross Amount Recognized in the Statement of Financial Position	'	'	13,287	[1]	21,683	[1]	'		'
Gross Amounts Offset in the Statement of Financial Position	'	'	0		0		'		'
Net of Amounts Presented in the Statement of Financial Position	'	'	13,287		21,683		'		'
Commodity Contracts	'	'	-8,672		-14,126		'		'
Cash Collateral Received	'	'	0		0		'		'
Net Amount	'	'	4,615		7,557		'		'
Liabilities	'	'	'		'		'		'
Gross Amount Recognized in the Statement of Financial Position	'	'	143,075	[1]	239,271	[1]	14,722	[1],[2]	21,524	[1],[2]
Gross Amounts Offset in the Statement of Financial Position	'	'	0		0		0	[2]	0	[2]
Net of Amounts Presented in the Statement of Financial Position	'	'	143,075		239,271		14,722	[2]	21,524	[2]
Commodity Contracts	'	'	-8,672		-14,126		0	[2]	0	[2]
Cash Collateral Posted	'	'	0		0		0	[2]	0	[2]
Net Amount	'	'	$134,403		$225,145		$14,722	[2]	$21,524	[2]
[1]	All Derivative Contract deals are executed under ISDA, NAESB and WSPP Master Netting Agreements with Right of Offset.
[2]	In``terest Rate Swap Contracts are only held at Puget Energy.

Accounting_for_Derivative_Inst5

Accounting for Derivative Instruments and Hedging Activities Recognized in Statement of Income (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Document Period End Date	'	'	30-Sep-13	'
Purchased electricity	$92,774,000	$85,933,000	$380,360,000	$441,145,000
Unrealized (gain) loss on derivative instruments	-8,888,000	-67,490,000	-57,203,000	-126,840,000
PUGET ENERGY [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Amount Not Designated as Normal Purchase, Normal Sale	'	'	'	2,200,000
Subsidiaries [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Document Period End Date	'	'	30-Sep-13	'
Purchased electricity	92,774,000	85,933,000	380,360,000	441,145,000
Unrealized (gain) loss on derivative instruments	-8,888,000	-65,594,000	-54,252,000	-115,309,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	2,068,000	-12,159,000	927,000	67,602,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member] | Other Income (Deductions) [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	470,000	-1,512,000	-1,790,000	5,258,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member] | Interest Rate Contract [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	3,625,000	7,548,000	4,301,000	26,812,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member] | Commodity Contract [Member] | Unrealized (Gain) Loss on Derivative Instruments, Net [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	-8,888,000	-67,442,000	-57,203,000	-124,641,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member] | Commodity Contract [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	9,142,000	26,998,000	22,710,000	52,972,000
Not Designated as Hedging Instrument [Member] | PUGET ENERGY [Member] | Commodity Contract [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	-2,281,000	22,249,000	32,909,000	107,201,000
Not Designated as Hedging Instrument [Member] | Subsidiaries [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	-2,027,000	-16,347,000	1,367,000	44,865,000
Not Designated as Hedging Instrument [Member] | Subsidiaries [Member] | Commodity Contract [Member] | Unrealized (Gain) Loss on Derivative Instruments, Net [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	-8,888,000	-65,594,000	-54,252,000	-115,309,000
Not Designated as Hedging Instrument [Member] | Subsidiaries [Member] | Commodity Contract [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	9,142,000	26,998,000	22,710,000	52,972,000
Not Designated as Hedging Instrument [Member] | Subsidiaries [Member] | Commodity Contract [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Unrealized (gain) loss on derivative instruments	-2,281,000	22,249,000	32,909,000	107,202,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-1,247,000	-2,015,000	-3,722,000	-16,666,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-1,623,000	'	-16,386,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	100,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-392,000	'	-380,000
Cash Flow Hedging [Member] | Subsidiaries [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-122,000	-2,362,000	-3,152,000	-9,977,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-122,000	'	-366,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	97,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-2,240,000	'	-9,708,000
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Cash Flow Hedging [Member] | Subsidiaries [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, (Loss) Gain [Line Items]	'	'	'	'
Purchased electricity	$0	'	'	'

Accounting_for_Derivative_Inst6

Accounting for Derivative Instruments and Hedging Activities Recognized in Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Document Period End Date	'	'	30-Sep-13	'
Interest rate contracts: [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income Reclassification Of Net Unrealized Gain Loss On Interest Rate Swaps During Period Net Of Tax	($811,000)	($1,055,000)	($2,526,000)	($10,651,000)
PUGET ENERGY [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Cash Flow Hedge Loss to be Reclassified within Twelve Months	'	'	-1,500,000	'
Subsidiaries [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Document Period End Date	'	'	30-Sep-13	'
Cash Flow Hedge Loss to be Reclassified within Twelve Months	'	'	-2,200,000	'
Cash Flow Hedging [Member] | PUGET ENERGY [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-1,247,000	-2,015,000	-3,722,000	-16,666,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-1,623,000	'	-16,386,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	100,000
Cash Flow Hedging [Member] | PUGET ENERGY [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-392,000	'	-380,000
Cash Flow Hedging [Member] | Subsidiaries [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-122,000	-2,362,000	-3,152,000	-9,977,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Interest expense [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-122,000	'	-366,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Electric generation fuel [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	97,000
Cash Flow Hedging [Member] | Subsidiaries [Member] | Purchased electricity [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	'	-2,240,000	'	-9,708,000
Revolving Credit Facility [Member] | Parent [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Line of Credit Facility, Decrease, Repayments	80,000,000	'	'	'
Line of Credit Facility, Amount Outstanding	299,000,000	'	299,000,000	'
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Revolving Credit Facility [Member] | PUGET ENERGY [Member] | Interest rate contracts: [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income Reclassification Of Net Unrealized Gain Loss On Interest Rate Swaps During Period Net Of Tax	($500,000)	'	'	'

Accounting_for_Derivative_Inst7

Accounting for Derivative Instruments and Hedging Activities Contractual Contingent Liability (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Electric portfolio [Member]	'
Derivative [Line Items]	'
Fair Value Liability	($69,124)	[1]
Posted Collateral	0
Additional Collateral, Aggregate Fair Value	37,598
Electric portfolio [Member] | Credit rating [Member]	'
Derivative [Line Items]	'
Fair Value Liability	-37,598	[1],[2]
Posted Collateral	0	[2]
Additional Collateral, Aggregate Fair Value	37,598	[2]
Electric portfolio [Member] | Requested credit for adequate assurance [Member]	'
Derivative [Line Items]	'
Fair Value Liability	-31,358	[1]
Posted Collateral	0
Additional Collateral, Aggregate Fair Value	0
Electric portfolio [Member] | Forward value of contract [Member]	'
Derivative [Line Items]	'
Fair Value Liability	-168	[1],[3]
Posted Collateral	0	[3]
Additional Collateral, Aggregate Fair Value	0	[3]
Electric portfolio [Member] | External Credit Rating, Investment Grade [Member]	'
Derivative [Line Items]	'
Derivative, Credit Risk Exposure, Percentage	99.90%
Electric portfolio [Member] | External Credit Rating, Non Investment Grade [Member]	'
Derivative [Line Items]	'
Derivative, Credit Risk Exposure, Percentage	0.10%
Natural gas portfolio [Member] | Credit rating [Member]	'
Derivative [Line Items]	'
Posted Collateral	$0	[2]
[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_Carryi

Fair Value Measurements Carrying Value (Details) (Carrying Value [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
PUGET ENERGY [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	$14,033	$135,542
Restricted Cash	7,765	3,700
Notes Receivable and Other	52,844	63,802
Total assets	74,642	203,044
Liabilities:	'	'
Short-term Debt	129,000	181,000
Total liabilities	129,000	181,000
PUGET ENERGY [Member] | Level 1 [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	0	105,000
Restricted Cash	5,305	914
Notes Receivable and Other	0	0
Total assets	5,305	105,914
Liabilities:	'	'
Short-term Debt	129,000	181,000
Total liabilities	129,000	181,000
PUGET ENERGY [Member] | Level 2 [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	14,033	30,542
Restricted Cash	2,460	2,786
Notes Receivable and Other	52,844	63,802
Total assets	69,337	97,130
Liabilities:	'	'
Short-term Debt	0	0
Total liabilities	0	0
Subsidiaries [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	13,863	135,530
Restricted Cash	7,765	3,700
Notes Receivable and Other	52,844	63,802
Total assets	74,472	203,032
Liabilities:	'	'
Short-term Debt	129,000	181,000
Short-term Debt owed by PSE to PE	29,598	29,598
Total liabilities	158,598	210,598
Subsidiaries [Member] | Level 1 [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	0	105,000
Restricted Cash	5,305	914
Notes Receivable and Other	0	0
Total assets	5,305	105,914
Liabilities:	'	'
Short-term Debt	129,000	181,000
Short-term Debt owed by PSE to PE	0	0
Total liabilities	129,000	181,000
Subsidiaries [Member] | Level 2 [Member]	'	'
Assets:	'	'
Cash and Cash Equivalents	13,863	30,530
Restricted Cash	2,460	2,786
Notes Receivable and Other	52,844	63,802
Total assets	69,167	97,118
Liabilities:	'	'
Short-term Debt	0	0
Short-term Debt owed by PSE to PE	29,598	29,598
Total liabilities	$29,598	$29,598

Fair_Value_Measurements_Debt_a

Fair Value Measurements Debt at at Carrying and Fair Value (Details) (Discounted cash flow [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
PUGET ENERGY [Member] | Carrying Value [Member]	'	'
Liabilities:	'	'
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	$5,239,693	$5,346,200
PUGET ENERGY [Member] | Carrying Value [Member] | Level 2 [Member]	'	'
Liabilities:	'	'
Junior subordinated notes	250,000	250,000
Long-term debt (fixed-rate), net of discount	4,690,693	4,662,200
Long Term Debt (variable rate) net of discount	299,000	434,000
PUGET ENERGY [Member] | Fair Value [Member]	'	'
Liabilities:	'	'
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	6,222,689	6,896,021
PUGET ENERGY [Member] | Fair Value [Member] | Level 2 [Member]	'	'
Liabilities:	'	'
Junior subordinated notes	258,389	264,842
Long-term debt (fixed-rate), net of discount	5,665,300	6,197,179
Long Term Debt (variable rate) net of discount	299,000	434,000
Subsidiaries [Member] | Carrying Value [Member]	'	'
Liabilities:	'	'
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	3,773,258	3,776,258
Subsidiaries [Member] | Carrying Value [Member] | Level 2 [Member]	'	'
Liabilities:	'	'
Junior subordinated notes	250,000	250,000
Long-term debt (fixed-rate), net of discount	3,523,258	3,526,258
Subsidiaries [Member] | Fair Value [Member]	'	'
Liabilities:	'	'
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	4,402,746	4,893,351
Subsidiaries [Member] | Fair Value [Member] | Level 2 [Member]	'	'
Liabilities:	'	'
Junior subordinated notes	258,389	264,842
Long-term debt (fixed-rate), net of discount	$4,144,357	$4,628,509

Fair_Value_Measurements_Assets

Fair Value Measurements Assets and Liabilities (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Electric portfolio [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Total [Member]

Total [Member]

Total [Member]

Total [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 2 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Total [Member]

Total [Member]

Total [Member]

Total [Member]

Total [Member]

Total [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Assets

'

'

'

'

'

'

'

'

'

'

'

'

$13,287,000

$21,683,000

'

'

'

'

'

'

'

'

'

'

'

'

$4,323,000

$8,028,000

$2,223,000

$1,259,000

$2,100,000

$6,769,000

$8,964,000

$13,655,000

$5,621,000

$8,298,000

$3,343,000

$5,357,000

$13,287,000

$21,683,000

$7,844,000

$9,557,000

$5,443,000

$12,126,000

Derivative Liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14,722,000

21,524,000

14,722,000

21,524,000

0

0

0

0

14,722,000

21,524,000

14,722,000

21,524,000

102,193,000

190,090,000

37,699,000

88,971,000

64,494,000

101,119,000

40,882,000

49,181,000

34,740,000

42,221,000

6,142,000

6,960,000

143,075,000

239,271,000

72,439,000

131,192,000

70,636,000

108,079,000

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at beginning of period

-39,772,000

-83,272,000

-35,526,000

-95,352,000

-36,899,000

-80,453,000

-33,924,000

-90,311,000

-2,873,000

-2,819,000

-1,602,000

-5,041,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Included in earnings

-392,000

[1]

5,332,000

[1]

-11,593,000

[1]

-11,538,000

[1]

-392,000

[1]

5,332,000

[1]

-11,593,000

[1]

-11,538,000

[1]

0

[1]

0

[1]

0

[1]

0

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Included in regulatory assets/liabilities

-957,000

-183,000

-967,000

-1,470,000

0

0

0

0

-957,000

-183,000

-967,000

-1,470,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlements

-804,000

[2]

12,708,000

[2]

7,030,000

[2]

48,229,000

[2]

-1,270,000

[2]

11,606,000

[2]

7,792,000

[2]

47,021,000

[2]

466,000

[2]

1,102,000

[2]

-762,000

[2]

1,208,000

[2]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transferred into Level 3

730,000

0

-7,799,000

-55,845,000

730,000

0

-7,799,000

-55,548,000

0

0

0

-297,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Transferred out of Level 3

9,277,000

12,302,000

16,937,000

62,863,000

8,712,000

11,831,000

16,405,000

58,692,000

565,000

471,000

532,000

4,171,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at end of period

-31,918,000

-53,113,000

-31,918,000

-53,113,000

-29,119,000

-51,684,000

-29,119,000

-51,684,000

-2,799,000

-1,429,000

-2,799,000

-1,429,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrealized (gain) loss on derivatives instuments, net

'

'

'

'

($800,000)

$5,100,000

($15,000,000)

($7,600,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(0.8) million and $5.1 million for the three months ended SeptemberB 30, 2013 and 2012, respectively. 2B Income Statement location: Unrealized (gain) loss on derivative instruments, net. Includes unrealized gains (losses) on derivatives still held in position as of the reporting date for electric derivatives of $(15.0) million and $(7.6) million for the nine months ended SeptemberB 30, 2013 and 2012, respectively.

[2]

The Company had no purchases, sales or issuances during the reported periods

Fair_Value_Measurements_Valuat

Fair Value Measurements Valuation Technicques for Measurement with Unobservable Inputs (Details) (USD $)

Sep. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

power_purchase_contract

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Electric portfolio [Member]

Electric portfolio [Member]

Natural gas portfolio [Member]

Natural gas portfolio [Member]

Priest Rapids Development [Member]

Low [Member]

High [Member]

Weighted Average [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Low [Member]

High [Member]

Weighted Average [Member]

Low [Member]

High [Member]

Weighted Average [Member]

Subsidiaries [Member]

Subsidiaries [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Commodity Contract [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Assets

'

'

'

'

'

$13,287,000

$21,683,000

'

'

'

'

'

'

$8,964,000

$13,655,000

'

'

$5,621,000

$8,298,000

$3,343,000

$5,357,000

'

Derivative Liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

40,882,000

49,181,000

0

0

34,740,000

42,221,000

6,142,000

6,960,000

'

Price (per MWh)

'

'

30.85

65.35

48.47

'

'

12.49

42.8

31.03

'

'

'

'

'

'

'

'

'

'

'

'

Price (per MMBtu)

'

'

'

'

'

'

'

'

'

'

3.53

4.54

4.15

'

'

'

'

'

'

'

'

'

Fair Value measurement, sensitivity analysis, hypothetical increase or decrease of market prices, result on fair value

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value Measurements, Sensitivity Analysis, Hypothetical Increase or Decrease of Market Prices, Result on Fair Value

16,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-lived Intangible Assets, Fair Value Disclosure

'

484,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

33,600,000

Number of Purchased Power Contracts Impaired

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite-Lived Intangible Assets, Net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

47,100,000

Impairment of Intangible Assets, Finite-lived

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,500,000

Fair Value Inputs, Power Contract Costs

'

'

$389,000

$6,845,000

$4,110,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Retirement_Benefits_Net_Period

Retirement Benefits Net Periodic Benefit Cost (Details) (USD $)	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	Other Benefit [Member]	Other Benefit [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	PUGET ENERGY [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]	Subsidiaries [Member]
							Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	Other Benefit [Member]	Other Benefit [Member]	Other Benefit [Member]	Other Benefit [Member]	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	Other Benefit [Member]	Other Benefit [Member]	Other Benefit [Member]	Other Benefit [Member]
Components of net periodic benefit cost:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Service cost	$14,464	$16,926	$1,123	$1,073	$100	$139	$4,822	$4,232	$14,464	$12,695	$375	$268	$1,123	$805	$34	$35	$100	$105	$4,822	$4,232	$14,464	$12,695	$375	$268	$1,123	$805	$34	$35	$100	$105
Interest cost	18,565	25,986	1,534	2,152	498	751	6,188	6,496	18,565	19,490	511	538	1,534	1,614	166	188	498	563	6,188	6,496	18,565	19,490	511	538	1,534	1,614	166	188	498	563
Expected return on plan assets	'	'	'	'	'	'	-9,774	-9,051	-29,321	-27,153	0	0	0	0	-109	-109	-327	-327	-10,172	-10,384	-30,514	-31,150	0	0	0	0	-109	-109	-327	-327
Amortization of prior service cost	'	'	'	'	'	'	-495	-495	-1,485	-1,485	-4	0	-13	0	0	0	0	0	-393	-393	-1,180	-1,180	-4	74	-13	220	7	9	22	27
Amortization of net loss (gain)	'	'	'	'	'	'	722	192	2,167	576	365	176	1,096	527	17	13	52	40	5,153	3,754	15,459	11,261	548	358	1,645	1,074	-71	-61	-213	-184
Amortization of transition obligation	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	0	0	0	0	0	0	0	0	0	12	0	37
Defined Benefit Plan, Net Periodic Benefit Cost	'	'	'	'	'	'	$1,463	$1,374	$4,390	$4,123	$1,247	$982	$3,740	$2,946	$108	$127	$323	$381	$5,598	$3,705	$16,794	$11,116	$1,430	$1,238	$4,289	$3,713	$27	$74	$80	$221

Retirement_Benefits_Change_in_

Retirement Benefits Change in Net Benefit Obligation (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Qualified Pension Benefits [Member]	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'
Benefit obligation at beginning of period	$616,290	$565,997
Service cost	14,464	16,926
Interest cost	18,565	25,986
Amendments	0	0
Actuarial loss/(gain)	3,436	40,914
Benefits paid	-34,875	-33,533
Medicare part D subsidiary received	0	0
Benefit obligation at end of period	617,880	616,290
SERP Pension Benefits [Member]	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'
Benefit obligation at beginning of period	51,795	48,370
Service cost	1,123	1,073
Interest cost	1,534	2,152
Amendments	0	-122
Actuarial loss/(gain)	0	5,483
Benefits paid	-5,061	-5,161
Medicare part D subsidiary received	0	0
Benefit obligation at end of period	49,391	51,795
Other Benefit [Member]	'	'
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]	'	'
Benefit obligation at beginning of period	17,672	16,436
Service cost	100	139
Interest cost	498	751
Amendments	0	0
Actuarial loss/(gain)	-1,055	1,199
Benefits paid	-1,202	-1,523
Medicare part D subsidiary received	125	670
Benefit obligation at end of period	$16,138	$17,672

Retirement_Benefits_Activity_D

Retirement Benefits Activity (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
In Millions, unless otherwise specified			Qualified Pension Benefits [Member]	Qualified Pension Benefits [Member]	SERP Pension Benefits [Member]	SERP Pension Benefits [Member]	Other Benefit [Member]	Other Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'	'	'	'	'
Fair Value of Plan Assets	$585.10	$531.20	'	'	'	'	'	'
Aggregate expected contributions	'	'	20.4	20.4	5	5	0.8	0.8
Company Contribution	'	'	$5.10	$15.30	$1.90	$5.10	$0.10	$0.80

Regulation_and_Rates_Details

Regulation and Rates (Details) (Subsidiaries [Member], USD $)

0 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Nov. 01, 2012

Jan. 31, 2013

Jun. 30, 2013

14-May-12

14-May-12

Jun. 28, 2012

14-May-12

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Nov. 01, 2013

Aug. 28, 2013

Apr. 25, 2013

Nov. 01, 2013

Electric [Member]

Natural Gas [Member]

Natural Gas [Member]

PCA Mechanism [Member]

PCA Mechanism [Member]

Expedited Rate Filing [Member]

Expedited Rate Filing [Member]

Power Cost Only Rate Case (PCORC) [Member]

Power Cost Only Rate Case (PCORC) [Member]

Power Cost Only Rate Case (PCORC) [Member]

Purchased Gas Adjustment (PGA) [Member]

Electric [Member]

Gas [Member]

Electric [Member]

Gas [Member]

Electric [Member]

Electric [Member]

Electric [Member]

Gas [Member]

Regulatory Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rate Case, Approved Effective Weighted Cost of Capital

'

'

7.77%

7.80%

'

'

'

'

'

'

'

'

'

'

'

Rate Case, Approved Effective Common Equity in Capital Structure

'

'

48.00%

48.00%

'

'

'

'

'

'

'

'

'

'

'

Rate Case, Approved Effective Return on Equity

'

'

9.80%

9.80%

'

'

'

'

'

'

'

'

'

'

'

Public Utilities, Rate Case, Requested Rate Increase

'

'

'

'

'

'

'

'

'

'

'

'

'

($0.60)

'

public utilities rate case requested increase (decrease) percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

-0.03%

'

Public Utilities, Rate Case, Increase (Decrease) in Requested Rate Increase

'

'

'

'

'

'

'

'

'

'

'

'

-1

'

'

Public Utilities Rate Case Increase Decrease in Requested Rate Filing Percentage

'

'

'

'

'

'

'

'

'

'

'

'

-0.05%

'

'

Accounting Petition, Approved Effective Increase to Revenue

'

'

'

'

'

6.9

'

'

'

'

'

'

'

'

'

Accounting Petition, Approved Effective Increase to Conservation Amortization Expense

'

'

'

'

'

6.6

'

'

'

'

'

'

'

'

'

Purchased Gas Adjustment, Annual Decrease in Revenue

77

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchased Gas Adjustment, Annual Decrease in Revenue, Percentage

7.70%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

American Recovery and Reinvestment Tax Act of 2009, Grant Amortization Period

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

American Recovery and Reinvestment Tax Act of 2009, Grant, Amortization Period Included in Customer Pass Through

'

'11 months

'

'

'

'

'

'

'

'

'

'

'

'

'

American Recovery and Reinvestment Tax Act of 2009, Grant Pass Through Amount

'

34.6

'

'

'

'

'

'

'

'

'

'

'

'

'

American Recovery and Reinvestment Tax Act of 2009, Grant Pass Through Interest Amount

'

23.8

'

'

'

'

'

'

'

'

'

'

'

'

'

American Recovery and Reinvestment Tax Act of 2009, Grant, Overall Average Rate Reduction

'

2.76%

'

'

'

'

'

'

'

'

'

'

'

'

'

Public Utilities, Rate Case, Approved Effective Annual Rate Increase (Decrease)

'

'

'

'

$63.30

'

$13.40

$21.40

$10.80

$30.70

($2)

($10.50)

'

'

$4.10

Public Utilities, Rate Case, Approved Effective Annual Rate Percentage Increase (Decrease)

'

'

'

'

3.20%

'

1.30%

1.00%

1.10%

1.50%

-0.20%

-0.50%

'

'

0.40%

Litigation_Details

Litigation (Details) (USD $)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Mar. 06, 2013	Mar. 06, 2013	Mar. 06, 2013	Mar. 06, 2013
	Colstrip Units 1 and 2 [Member]	Colstrip Units 3 and 4 [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]	Pending Litigation [Member]
					Sierra Club and Montana Environmental Information Center [Member]	Clean Air Act - Prevention of Significant Deterioration (PSD) Violations	Failure to Update Title V Permit [Member]	Major Modifications to Title V Permit [Member]
						Sierra Club and Montana Environmental Information Center [Member]	Sierra Club and Montana Environmental Information Center [Member]	Sierra Club and Montana Environmental Information Center [Member]
						claim	claim	claim
Loss Contingencies [Line Items]	'	'	'	'	'	'	'	'
Ownership interest (percent)	50.00%	25.00%	'	'	'	'	'	'
Numbe of claims	'	'	'	'	'	39	1	36
Damages sought, civil penalties to be used for beneficial mitigation projects	'	'	'	'	$100,000	'	'	'
Litigation claims accrual	'	'	$1,400,000	$3,400,000	'	'	'	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income - Changes by Component (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Reclassification out of Accumulated Other Comprehensive Income [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

PUGET ENERGY [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Energy Related Derivative [Member]

Energy Related Derivative [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Energy Related Derivative [Member]

Energy Related Derivative [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Energy Related Derivative [Member]

Energy Related Derivative [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Energy Related Derivative [Member]

Energy Related Derivative [Member]

Accumulated Other Comprehensive Income (Loss) [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

($29,825)

($29,065)

'

'

'

'

'

'

($170,733)

($175,998)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income tax (benefit) expense

5,936

20,943

75,569

73,289

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14,530

30,949

105,470

108,250

'

'

'

'

'

'

'

'

'

'

436

1,360

0

-57

-212

-636

'

'

43

-129

0

976

-1,834

-5,501

Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning of Period

'

'

-32,829

'

'

'

'

'

-31,981

-32,829

-1,307

-3,022

-849

-742

'

'

'

'

-179,964

'

-187,198

'

'

'

'

'

-6,466

-6,624

-2,765

-4,576

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss) before reclassifications

'

'

'

'

'

'

'

'

0

-1,548

0

0

0

0

0

-1,548

'

'

0

'

-1,548

'

0

-1,548

'

'

0

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Comprehensive Income Reclassification Of Net Unrealized Gain Loss On Interest Rate Swaps During Period Net Of Tax

'

'

'

'

-811

-1,055

-2,526

-10,651

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amounts reclassified from accumulated other comprehensive income (loss), net of tax

'

'

'

'

'

'

'

'

1,204

3,600

'

'

'

'

393

1,181

'

'

3,485

'

12,267

'

3,406

-10,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax

0

255

-107

182

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

1,456

1,811

6,247

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization Of Financing Cash Flow Hedge Contracts To Earnings During Period Net Of Tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

79

79

237

238

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net current-period other comprehensive income (loss)

'

'

'

'

'

'

'

'

1,204

2,052

811

2,526

0

-107

'

'

'

'

3,485

'

10,719

'

'

'

'

'

79

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

End of Period

-30,777

'

-30,777

'

'

'

'

'

-30,777

-30,777

-496

-496

-849

-849

-29,432

-29,432

'

'

-176,479

'

-176,479

'

-167,327

-167,327

'

'

-6,387

-6,387

-2,765

-2,765

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income (loss)

$8,540

$46,692

$176,919

$192,863

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$26,605

$66,868

$233,205

$260,456

'

'

'

'

'

'

'

'

($1,204)

($3,600)

($811)

($2,526)

$0

$107

($393)

($1,181)

($3,485)

($12,266)

($79)

($237)

'

($1,810)

($3,406)

($10,219)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income - Reclassification Location (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest expense	($94,788)	($96,507)	($299,521)	($299,672)
Purchased electricity	92,774	85,933	380,360	441,145
Income (loss) before income taxes	14,476	67,635	252,488	266,152
Net income (loss)	8,540	46,692	176,919	192,863
Income Tax Expense (Benefit)	-5,936	-20,943	-75,569	-73,289
PUGET ENERGY [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net income (loss)	-1,204	'	-3,600	'
PUGET ENERGY [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Amortization of prior service cost	499	'	1,498	'
Amortization of net gain (loss)	-1,104	'	-3,315	'
Income (loss) before income taxes	-605	'	-1,817	'
Net income (loss)	-393	'	-1,181	'
Income Tax Expense (Benefit)	212	'	636	'
PUGET ENERGY [Member] | Interest Rate Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest expense	1,247	'	3,886	'
Net income (loss)	-811	'	-2,526	'
Income Tax Expense (Benefit)	-436	'	-1,360	'
PUGET ENERGY [Member] | Energy Related Derivative [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Purchased electricity	0	'	164	'
Net income (loss)	0	'	107	'
Income Tax Expense (Benefit)	0	'	57	'
Subsidiaries [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest expense	-64,614	-61,524	-196,363	-184,595
Purchased electricity	92,774	85,933	380,360	441,145
Income (loss) before income taxes	41,135	97,817	338,675	368,706
Net income (loss)	26,605	66,868	233,205	260,456
Income Tax Expense (Benefit)	-14,530	-30,949	-105,470	-108,250
Subsidiaries [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net income (loss)	-3,485	'	-12,266	'
Subsidiaries [Member] | Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Amortization of prior service cost	390	'	1,171	'
Amortization of net gain (loss)	-5,630	'	-16,891	'
Income (loss) before income taxes	-5,240	'	-15,720	'
Net income (loss)	-3,406	'	-10,219	'
Income Tax Expense (Benefit)	1,834	'	5,501	'
Subsidiaries [Member] | Interest Rate Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest expense	122	'	366	'
Net income (loss)	-79	'	-237	'
Income Tax Expense (Benefit)	-43	'	129	'
Subsidiaries [Member] | Energy Related Derivative [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Purchased electricity	0	'	-2,786	'
Net income (loss)	'	'	-1,810	'
Income Tax Expense (Benefit)	$0	'	($976)	'

Other_Jefferson_County_Public_

Other Jefferson County Public Utility District (Details) (Jefferson County Public Utility District [Member], USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Jefferson County Public Utility District [Member]	'
Significant Acquisitions and Disposals [Line Items]	'
Property, Plant and Equipment, Net Book Value	$46.70
Significant Acquisitions and Disposals, Gain (Loss) on Sale or Disposal, Pretax	$60

Other_Bond_Issuances_Details

Other Bond Issuances (Details) (USD $)	23-May-13	23-May-13	23-May-13	Jun. 30, 2013
In Millions, unless otherwise specified	Pollution Control Bonds [Member]	5.000% Series Due 2031 [Member]	3.910% Series Due 2031 [Member]	Bonds [Member]
	Subsidiaries [Member]	Bonds [Member]	Bonds [Member]	Parent [Member]
		Subsidiaries [Member]	Subsidiaries [Member]
Debt Instrument [Line Items]	'	'	'	'
Long-term Debt, Gross	$161.90	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	5.01%	3.91%	'
Liabilities and Equity, Fair Value Adjustment	'	'	'	$18