Short-term Debt and Revolving Credit Facilities (MEC) (Details) (MidAmerican Energy Company and Subsidiaries [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 535	$ 650
Letters of Credit Outstanding, Amount	(195)	(195)
Line of Credit Facility, Remaining Borrowing Capacity	340	455
Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio	0.65
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date	Oct. 30, 2014
Regulatory Approval for Additional Short-Term Debt Issuances	600
Unsecured credit facility, $645 million, expiring July 2012 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	530	645
Line of Credit Facility, Expiration Date	Jul. 06, 2012
Unsecured credit facility, $530 million, expiring July 2013 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date	Jul. 06, 2013
Unsecured 364-day Credit Facility, $5 million, expiring June 2013 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 5
Line of Credit Facility, Expiration Date	Jun. 30, 2013