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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 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	$ (13)	$ 2	$ 11	$ 32
Changes in fair value recognized in OCI	(21)	25	(79)	0
Net gains (losses) reclassified to nonregulated cost of sales	6	(1)	40	(6)
Ending balance	(28)	26	(28)	26
Cash flow hedge ineffectiveness	insignificant	insignificant	insignificant	insignificant
Cash flow hedge gain (loss) to be reclassified within twelve months			$ 21