Schedule II Valuation and Qualifying Accounts (LLC) (Details) (MidAmerican Funding, LLC and Subsidiaries [Domain], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Reserve for uncollectible accounts receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 8		$ 12		$ 9
Charged to Income	8		4		11
Deductions	(6)		(8)		(8)
Balance at End of Year	10		8		12
Reserves Not Deducted From Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	8	[1]	8	[1]	9	[1]
Charged to Income	6	[1]	4	[1]	4	[1]
Deductions	(5)	[1]	(4)	[1]	(5)	[1]
Balance at End of Year	$ 9	[1]	$ 8	[1]	$ 8	[1]

[1] (1)Reserves not deducted from assets include primarily estimated liabilities for losses retained by MidAmerican Funding and MHC for workers compensation, public liability and property damage claims.