Schedule I MidAmerican Funding, LLC Condensed Financial Statements Condensed Statements of Operations (Details) (MidAmerican Funding LLC [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
MidAmerican Funding LLC [Member]
Condensed Financial Statements, Captions [Line Items]
Interest on long-term debt	$ 22	$ 25	$ 36
Income (loss) before income tax expense (benefit)	(22)	(25)	(36)
Income tax expense (benefit)	(9)	(11)	(15)
Equity in undistributed earnings of subsidiaries	355	318	361
Net income attributable to MidAmerican Funding	$ 342	$ 304	$ 340