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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
MidAmerican Energy Company [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	$ (28)	$ 26	$ 11	$ 32
Changes in fair value recognized in OCI	19	1	(60)	1
Net gains (losses) reclassified to nonregulated cost of sales	(5)	(1)	35	(7)
Ending balance	(14)	26	(14)	26
Cash flow hedge ineffectiveness	insignificant	insignificant	insignificant	insignificant
Cash flow hedge gain (loss) to be reclassified within twelve months			$ 14