Income Taxes (LLC) Components of Net Deferred Income Tax Liability (Details) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 State and Local [Member]
Deferred income tax assets: [Abstract]
Regulatory liabilities	$ 311	$ 300
Employee benefits	83	96
Derivative contracts	32	48
Asset retirement obligations	132	122
Other	88	68
Total deferred income tax assets	646	634
Deferred income tax Liabilities: [Abstract]
Depreciable property	(2,432)	(2,195)
Regulatory assets	(353)	(333)
Other	(26)	(19)
Total deferred income tax liabilities	(2,811)	(2,547)
Net deferred income tax liabilities	2,165	1,913
Reflected as: [Abstract]
Current assets - other	0	5
Current liabilities - other	(3)	0
Deferred income taxes	(2,162)	(1,918)
Summary of Tax Credit Carryforwards [Abstract]
State carryforwards					$ 21
Domestic carryforwards expiration date			2013	2031