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, 2016	Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 250	$ 223	$ 182
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	(30)	128	96
Net Gains (Losses) Reclassified To Operating Revenue	(5)	1	(32)
Ending balance	148	250	223
MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	20	38	10
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	3	40	61
Net Gains (Losses) Reclassified To Operating Revenue	(15)	(42)	(28)
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	0	(1)	(1)
Net Gains (Losses) Reclassified To Cost Of Natural Gas Purchases	(12)	(15)	(4)
Ending balance	(4)	20	38
Derivative, Gain (Loss) on Derivative, Net	0	(4)	15
Other Revenue Net [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	0	15	6
Cost Of Natural Gas [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	0	2	0
Cost Of Sales Nonregulated [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	$ 0	$ (21)	$ 9