Risk Management and Hedging Activities (MEC) Designated as Hedging Contracts (Details) (MidAmerican Energy Company [Member], 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] | Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	$ 26	$ 56	$ 32	$ 43
Changes in fair value recognized in OCI	1	(20)	1	20
Net losses reclassified to nonregulated cost of sales	(1)	(4)	(7)	(31)
Ending balance	26	32	26	32
Cash Flow Hedge Ineffectiveness is Immaterial			insignificant	insignificant
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ (14)