Fair Value Measurements Valuation Technicques for Measurement with Unobservable Inputs (Details) (USD $)				3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Commodity Contract [Member]	Dec. 31, 2013 Commodity Contract [Member]	Mar. 31, 2014 Electric portfolio [Member] Discounted cash flow [Member] Low [Member]	Mar. 31, 2014 Electric portfolio [Member] Discounted cash flow [Member] High [Member]	Mar. 31, 2014 Electric portfolio [Member] Discounted cash flow [Member] Weighted Average [Member]	Mar. 31, 2014 Natural gas portfolio [Member] Discounted cash flow [Member] Low [Member]	Mar. 31, 2014 Natural gas portfolio [Member] Discounted cash flow [Member] High [Member]	Mar. 31, 2014 Natural gas portfolio [Member] Discounted cash flow [Member] Weighted Average [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member] PUGET ENERGY [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] PUGET ENERGY [Member]	Mar. 31, 2014 Electric portfolio [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member] Commodity Contract [Member]		Dec. 31, 2013 Electric portfolio [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member] Commodity Contract [Member]	Mar. 31, 2014 Natural gas portfolio [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member] Commodity Contract [Member]		Dec. 31, 2013 Natural gas portfolio [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Subsidiaries [Member] Commodity Contract [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Assets		$ 51,709,000	$ 26,600,000							$ 7,590,000	$ 6,491,000			$ 5,040,000	[1]	$ 3,818,000	$ 2,550,000	[1]	$ 2,673,000
Derivative Liabilities										23,299,000	22,273,000	0	0	19,646,000	[1]	19,239,000	3,653,000	[1]	3,034,000
Price (per MWh)				4.38	49.95	35.67
Price (per MMBtu)							3.62	4.63	4.04
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	$ 12,100,000

[1] 1 The valuation techniques, unobservable inputs and ranges are the same for asset and liability positions