Risk Management and Hedging Activities (MEC) Collateral and Contingent Features (Details) (MidAmerican Energy Company [Member], Commodity Contract [Member], USD $) In Millions, unless otherwise specified			3 Months Ended		6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Designated as Hedging Instrument [Member]	Jun. 30, 2013 Designated as Hedging Instrument [Member]	Jun. 30, 2014 Designated as Hedging Instrument [Member]	Jun. 30, 2013 Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives, net liability positions with specific credit-risk features, aggregate fair value	$ 26	$ 35
Collateral already posted, aggregate fair value	0	0
Additional collateral, aggregate fair value	$ 7	$ 24
Cash flow hedge ineffectiveness			insignificant	insignificant	insignificant	insignificant