The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Amount before tax of other comprehensive income (loss) attributable to parent entity.

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Accounting for Derivative Instruments and Hedging Activities (Schedule of Amounts Recognized in Other Comprehensive Income) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ (500,000)
PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(1,100,000)
Cash Flow Hedging \| PUGET ENERGY
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(716,000)	(4,562,000)	(18,382,000)
Cash Flow Hedging \| PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(2,551,000)	(4,410,000)	(13,346,000)
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] \| PUGET ENERGY \| Energy Related Derivative
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		(57,000)	(671,000)
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] \| PUGET SOUND ENERGY, INC. \| Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		(488,000)	(488,000)
Electric Generation Fuel \| Cash Flow Hedging \| PUGET ENERGY
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	100,000
Electric Generation Fuel \| Cash Flow Hedging \| PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	97,000
Purchased Electricity \| Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] \| Cash Flow Hedging \| PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		(3,922,000)	(12,955,000)
Electric Derivative [Member] \| Electric Generation Fuel
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	0	0	100,000
Electric Derivative [Member] \| Electric Generation Fuel \| PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	0	0	97,000
Electric Derivative [Member] \| Purchased Electricity
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(572,000)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(572,000)	(57,000)	(671,000)
Interest Rate Contract \| Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(144,000)	(4,505,000)	(17,811,000)
Interest Rate Contract \| Interest Expense \| PUGET SOUND ENERGY, INC.
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (488,000)