Risk Management and Hedging Activities (MEC) Not Designated as Hedging Contracts (Details) (MidAmerican Energy Company [Member], Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
MidAmerican Energy Company [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 23	$ 63	$ 45	$ 73
Changes in fair value recognized in net regulatory assets	4	(4)	4	7
Net (losses) gains reclassified to operating revenue	(1)	(2)	2	18
Net gains reclassified to cost of fuel, energy and capacity	0	1	0	2
Net losses reclassified to cost of gas sold	(6)	(9)	(31)	(51)
Ending balance	$ 20	$ 49	$ 20	$ 49