SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) (Allowance for doubtful accounts receivable, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Period	$ 8,495	$ 9,784	$ 8,094
Additions Charged to Costs and Expenses	21,567	18,449	23,875
Deductions	20,130	19,738	22,185
Balance At End Of Period	9,932	8,495	9,784
PUGET SOUND ENERGY, INC.
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Period	8,495	9,784	8,094
Additions Charged to Costs and Expenses	21,567	18,449	23,875
Deductions	20,130	19,738	22,185
Balance At End Of Period	$ 9,932	$ 8,495	$ 9,784