CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended		11 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009 Successor [Member]	Feb. 05, 2009 Predecessor [Member]	Dec. 31, 2011 PUGET SOUND ENERGY, INC. [Member]	Dec. 31, 2010 PUGET SOUND ENERGY, INC. [Member]	Dec. 31, 2009 PUGET SOUND ENERGY, INC. [Member]
Operating revenue:
Electric	$ 2,147,220	$ 2,107,469	$ 1,885,118	$ 213,618	$ 2,147,220	$ 2,107,469	$ 2,098,736
Gas	1,168,850	1,011,531	1,034,744	190,001	1,168,850	1,011,531	1,224,745
Other	2,695	3,217	5,286	94	3,733	3,217	5,020
Total operating revenue	3,318,765	3,122,217	2,925,148	403,713	3,319,803	3,122,217	3,328,501
Energy costs:
Purchased electricity	771,405	773,429	796,040	90,737	771,983	774,007	887,306
Electric generation fuel	199,471	268,147	196,483	11,961	199,471	268,147	208,444
Residential exchange	(71,147)	(75,109)	(83,962)	(12,542)	(71,147)	(75,109)	(96,504)
Purchased gas	622,088	535,933	597,935	120,925	622,088	535,933	718,860
Unrealized (gain) loss on derivative instruments, net	11,494	54,095	(156,601)	3,867	54,146	166,953	(1,254)
Utility operations and maintenance	497,921	486,701	449,745	37,650	497,921	486,701	487,396
Non-utility expense and other	9,442	23,952	16,672	112	11,147	11,159	14,532
Merger and related costs	0	0	2,731	44,324	0	0	23,908
Depreciation	299,597	292,634	242,477	21,773	299,597	292,634	269,386
Amortization	72,381	71,572	63,466	4,969	72,381	71,572	63,466
Conservation amortization	107,646	90,109	58,875	7,592	107,646	90,109	66,466
Taxes other than income taxes	323,527	292,520	266,424	36,935	323,527	292,520	303,360
Total operating expenses	2,843,825	2,813,983	2,450,285	368,303	2,888,760	2,914,626	2,945,366
Operating income	474,940	308,234	474,863	35,410	431,043	207,591	383,135
Other income (deductions):
Other income	58,052	45,196	49,158	3,653	58,041	45,153	52,812
Other expense	(5,380)	(5,673)	(6,154)	(369)	(5,380)	(5,673)	(6,524)
Non-hedged interest rate derivative expense	(28,601)	(7,955)	0	0
Charitable contributions	0	0	(5,000)	0
Interest charges:
AFUDC	29,949	14,157	8,864	350	29,949	14,157	9,215
Interest expense	(371,910)	(321,167)	(265,675)	(17,291)	(231,212)	(234,793)	(211,478)
Interest expense on parent note					(204)	(218)	(264)
Income (loss) before income taxes	157,050	32,792	256,056	21,753	282,237	26,217	226,896
Income tax (benefit) expense	33,760	2,481	82,041	8,997	78,117	122	67,644
Net income (loss)	$ 123,290	$ 30,311	$ 174,015	$ 12,756	$ 204,120	$ 26,095	$ 159,252