Risk Management and Hedging Activities Risk Management and Hedging Activities - MEC - Not Designated as Hedging Contracts (Details) - Commodity Contract [Member] - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 223	$ 182	$ 235
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	128	96	29
Net Gains (Losses) Reclassified To Operating Revenue	1	(32)	8
Ending balance	250	223	182
MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	38	10	45
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	40	61	5
Net Gains (Losses) Reclassified To Operating Revenue	(42)	(28)	(1)
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(1)	(1)	(1)
Net Gains (Losses) Reclassified To Cost Of Natural Gas Purchases	(15)	(4)	(38)
Ending balance	20	38	10
Derivative, Gain (Loss) on Derivative, Net	(4)	15	(2)
Other Revenue Net [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	15	6	0
Cost Of Natural Gas [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	2	0	0
Cost Of Sales Nonregulated [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	$ (21)	$ 9	$ (2)