Short-Term Debt and Revolving Credit Facilities (LLC) (Details) (MidAmerican Funding, LLC and Subsidiaries [Domain], MHC, Inc. [Member], Unsecured 364-day credit facility, $4 million, expiring June 2013 [Member], Line of Credit [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
MidAmerican Funding, LLC and Subsidiaries [Domain] | MHC, Inc. [Member] | Unsecured 364-day credit facility, $4 million, expiring June 2013 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 4
Line of Credit Facility, Expiration Date	Jun. 30, 2013
Line of Credit Facility, Amount Outstanding	$ 0	$ 0