Risk Management and Hedging Activities Risk Management and Hedging Activities - Balance Sheet Location (Details) (Commodity Contract [Member], Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Derivatives, Fair Value [Line Items]
Commodity assets	$ 32	[1]	$ 115	[1]
Commodity liabilities	(153)	[1]	(379)	[1]
Derivative, Fair Value, Net	(121)	[1]	(264)	[1]
Cash collateral receivable (payable)	55		123
Total derivatives - net basis	(66)		(141)
Regulatory asset	121		264		487
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	10	[1]	30	[1]
Commodity liabilities	(2)	[1]	(17)	[1]
Derivative, Fair Value, Net	8	[1]	13	[1]
Cash collateral receivable (payable)	0		(2)
Total derivatives - net basis	8		11
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	3	[1]	7	[1]
Commodity liabilities	(2)	[1]	(3)	[1]
Derivative, Fair Value, Net	1	[1]	4	[1]
Cash collateral receivable (payable)	0		0
Total derivatives - net basis	1		4
Derivative Contracts - Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	18	[1]	66	[1]
Commodity liabilities	(122)	[1]	(242)	[1]
Derivative, Fair Value, Net	(104)	[1]	(176)	[1]
Cash collateral receivable (payable)	55		86
Total derivatives - net basis	(49)		(90)
Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	1	[1]	12	[1]
Commodity liabilities	(27)	[1]	(117)	[1]
Derivative, Fair Value, Net	(26)	[1]	(105)	[1]
Cash collateral receivable (payable)	0		39
Total derivatives - net basis	$ (26)		$ (66)

[1] PacifiCorp's commodity derivatives are generally included in rates and as of December 31, 2012 and 2011, a regulatory asset of $121 million and $264 million, respectively, was recorded related to the net derivative liability of $121 million and $264 million, respectively.