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
	Mar. 31, 2014	Mar. 31, 2013
MidAmerican Energy Company [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	$ 11	$ 32
Changes in fair value recognized in OCI	(58)	(25)
Net gains (losses) reclassified to nonregulated cost of sales	34	(5)
Ending balance	(13)	2
Cash flow hedge ineffectiveness	insignificant	insignificant
Cash flow hedge gain (loss) to be reclassified within twelve months	$ 16