CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Parent [Line Items]
Net income (loss)	$ 167,475	$ 88,480
Other comprehensive income (loss):
Reclassification of net unrealized (gain) loss on interest rate swaps during the period, net of tax	854	2,508
Net unrealized gain (loss) from pension and postretirement plans, net of tax	347	(107)
Reclassification of net unrealized (gain) loss on energy derivative instruments settled during the period, net of tax	(107)	(195)
Other comprehensive income (loss)	1,094	2,206
Comprehensive income (loss)	168,569	90,686
PUGET SOUND ENERGY, INC. [Member]
Parent [Line Items]
Net income (loss)	179,938	112,716
Other comprehensive income (loss):
Net unrealized gain (loss) from pension and postretirement plans, net of tax	3,386	2,416
Reclassification of net unrealized (gain) loss on energy derivative instruments settled during the period, net of tax	1,811	1,923
Amortization of treasury interest rate swaps to earnings, net of tax	79	79
Other comprehensive income (loss)	5,276	4,418
Comprehensive income (loss)	$ 185,214	$ 117,134