Risk Management and Hedging Activities (MEC) Not Designated as Hedging Contracts (Details) (MidAmerican Energy Company [Member], Not 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] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 32	$ 24	$ 10	$ 45
Changes in fair value recognized in net regulatory assets	20	1	62	0
Net (losses) gains reclassified to operating revenue	(5)	0	(24)	3
Net gains (losses) reclassified to cost of gas sold	1	(2)	0	(25)
Ending balance	$ 48	$ 23	$ 48	$ 23