CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Other comprehensive income (loss):
Net tax on reclassification of net unrealized loss on interest rate swaps during the period, tax	$ 460	$ 1,350
Net unrealized gain (loss) from pension and postretirement plans, tax	186	(58)
Reclassification of net unrealized loss on energy derivative instruments during the period, tax	(57)	(105)
PUGET SOUND ENERGY, INC. [Member]
Other comprehensive income (loss):
Net unrealized gain (loss) from pension and postretirement plans, tax	1,823	1,301
Reclassification of net unrealized loss on energy derivative instruments during the period, tax	975	1,035
Amortization of treasury interest rate swaps to earnings, net of tax	$ 43	$ 43