Property, Plant and Equipment, Net Property, Plant and Equipment, Net - MEC (Details) - MidAmerican Energy Company [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 12,296	$ 12,296	$ 12,328
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	746	746	493
Public Utilities, Property, Plant and Equipment, Net	13,042	13,042	12,821
Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Plant in Service, Excluding Construction Work In Progress	17,950	17,950	17,770
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(5,660)	(5,660)	(5,448)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	12,290	12,290	12,322
Unregulated operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(1)	(1)	(1)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	6	6	6
Gross public utility property, plant and equipment in service	7	7	7
Electric Operations [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation or Processing	11,308	11,308	11,282
Public Utilities, Property, Plant and Equipment, Transmission	1,794	1,794	1,726
Public Utilities, Property, Plant and Equipment, Distribution	3,260	3,260	3,197
Natural Gas Processing Plant [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution	1,588	1,588	$ 1,565
Electricity Generation Plant, Non-Nuclear [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Change in Accounting Estimates, Impact on Future Periods		34
Change in Accounting Estimates, Impact on Current Period From Prior Year Change	$ 8	$ 17