Risk Management and Hedging Activities Risk Management and Hedging Activities - Balance Sheet Location (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Payables with right of offset under master netting arrangements	$ 3
Receivables with right of offset under master netting arrangements	5		6
Letters of credit with right of offset under master netting arrangements			1
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(82)		(121)
Cash collateral, net receivable, offset against derivative positions	33		55
Derivative Assets (Liabilities), at Fair Value, Net	(49)	[1]	(66)	[2]
Commodity Contract [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	6		8
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative Assets (Liabilities), at Fair Value, Net	6	[1]	8	[2]
Commodity Contract [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	1		1
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative Assets (Liabilities), at Fair Value, Net	1	[1]	1	[2]
Commodity Contract [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(71)		(104)
Cash collateral, net receivable, offset against derivative positions	33		55
Derivative Assets (Liabilities), at Fair Value, Net	(38)	[1]	(49)	[2]
Commodity Contract [Member] | Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(18)		(26)
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative Assets (Liabilities), at Fair Value, Net	(18)	[1]	(26)	[2]
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	22	[3]	32	[3]
Commodity liabilities	(104)	[3]	(153)	[3]
Derivative, Fair Value, Net	(82)	[3]	(121)	[3]
Regulatory asset	82		121		284	264
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	7	[3]	10	[3]
Commodity liabilities	(1)	[3]	(2)	[3]
Derivative, Fair Value, Net	6	[3]	8	[3]
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	2	[3]	3	[3]
Commodity liabilities	(1)	[3]	(2)	[3]
Derivative, Fair Value, Net	1	[3]	1	[3]
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	12	[3]	18	[3]
Commodity liabilities	(83)	[3]	(122)	[3]
Derivative, Fair Value, Net	(71)	[3]	(104)	[3]
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Commodity assets	1	[3]	1	[3]
Commodity liabilities	(19)	[3]	(27)	[3]
Derivative, Fair Value, Net	$ (18)	[3]	$ (26)	[3]

[1] Under master netting arrangements, as of March 31, 2013, PacifiCorp had the right to offset $3 million of payables with current derivative assets and $5 million of receivables with current derivative liabilities upon counterparty default.

[2] Under master netting arrangements, as of December 31, 2012, PacifiCorp had the right to offset $6 million of receivables and $1 million of letters of credit with current derivative liabilities upon counterparty default.

[3] PacifiCorp's commodity derivatives are generally included in rates and as of March 31, 2013 and December 31, 2012, a regulatory asset of $82 million and $121 million, respectively, was recorded related to the net derivative liability of $82 million and $121 million, respectively.