Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Cash Flow Hedge Instruments, Amount Settled

+ References

No definition available.

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- Definition

Debt Instrument, Term

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No definition available.

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- Definition

Decrease for amounts repaid on the debt instrument for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

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-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The amount of net gains and losses recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a),(c),(d),(e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-SubTopic 10

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-Paragraph 4A

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- Definition

The effective portion of losses on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph b

-Clause 2

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669646-108580

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 205G

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-SubTopic 10

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-Paragraph 4C

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- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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- Definition

Aggregate notional amount of all derivatives designated as cash flow hedging instruments. The notional amount relates to a number of currency units, shares, bushels, pounds, or other units specified in a derivative instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

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-Paragraph 1B

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Accounting for Derivative Instruments and Hedging Activities Derivative Activity and Notional Amounts (Details) (USD $) In Millions, unless otherwise specified				0 Months Ended	6 Months Ended		6 Months Ended			3 Months Ended
	Jun. 30, 2012 Natural gas derivatives [Member] Not Designated as Hedging Instrument [Member] MMBTU	Jun. 30, 2012 Electric generation fuel [Member] Not Designated as Hedging Instrument [Member] MMBTU	Jun. 30, 2012 Purchased electricity [Member] Not Designated as Hedging Instrument [Member] MWh	Feb. 10, 2012 PUGET ENERGY [Member]	Jun. 30, 2012 PUGET ENERGY [Member]	Mar. 31, 2012 PUGET ENERGY [Member]	Jun. 30, 2012 PUGET ENERGY [Member] Interest Rate Swap [Member] Contracts	Jun. 30, 2012 PUGET ENERGY [Member] Interest Rate Swap [Member] Not Designated as Hedging Instrument [Member]	Jun. 15, 2012 PUGET ENERGY [Member] Senior Notes [Member]	Jun. 30, 2012 PUGET ENERGY [Member] Line of Credit [Member]
Derivative [Line Items]
Number of Interest Rate Derivatives Held							2
Debt Instrument, Face Amount									$ 450.0
Debt Instrument, Term									10 years
Debt Instrument, Decrease, Repayments										425.0
Line of Credit Facility, Amount Outstanding						859.0				434.0
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion					7.9
Cash Flow Hedge Instruments, Amount Settled				550.0
Derivative Instruments, Gain (Loss) Recognized in Income, Net							(20.2)
Interest rate swaps					450.0
Derivative, Notional Amount								$ 450.0
Derivative, Notional amount, Nonmonetary	508,805,338	137,635,000	11,629,550