Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Entity Information [Line Items]

Schedule of Authorized AFUDC Rates

The authorized AFUDC rates authorized by the Washington Utilities and Transportation Commission (Washington Commission) for natural gas and electric utility plant additions based on the effective dates is as follows:

Effective Date	Washington Commission AFUDC Rates
May 14, 2012 - present	7.80	%
April 8, 2010 - May 13, 2012	8.10
November 1, 2008 - April 7, 2010	8.25

Schedule of AFUDC

The following table presents the AFUDC amounts:

	Year Ended December 31,
(Dollars in Thousands)	2012		2011		2010
Equity AFUDC	$	25,469	$	32,431	$	12,677
Washington Commission AFUDC	1,895		5,108		3,715
Total in other income	27,364		37,539		16,392
Debt AFUDC	22,216		29,949		14,157
Total AFUDC	$	49,580	$	67,488	$	30,549

Schedule of Accumulated Other Comprehensive Income (Loss)

The following tables set forth the components of the Company’s accumulated other comprehensive income (loss) at December 31:

Puget Energy	December 31,
(Dollars in Thousands)	2012			2011
Net unrealized loss on energy derivative instruments	$	(742	)	$	(1,113	)
Net unrealized loss on interest rate swaps	(3,022		)	(14,599		)
Net unrealized loss and prior service cost on pension plans	(29,065		)	(15,195		)
Total Puget Energy, net of tax	$	(32,829	)	$	(30,907	)

PUGET SOUND ENERGY, INC.

Entity Information [Line Items]

Schedule of Accumulated Other Comprehensive Income (Loss)

Puget Sound Energy	December 31,
(Dollars in Thousands)	2012			2011
Net unrealized loss on energy derivative instruments	$	(4,576	)	$	(12,934	)
Net unrealized loss on treasury interest rate swaps	(6,624		)	(6,941		)
Net unrealized loss and prior service cost on pension plans	(175,998		)	(168,704		)
Total PSE, net of tax	$	(187,198	)	$	(188,579	)