Property, Plant and Equipment, Net Property, Plant and Equipment, Net - MEC (Details) - MidAmerican Energy Company [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 13,358	$ 13,410
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	910	797
Property, plant and equipment, net	14,268	14,207
Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Plant in Service, Excluding Construction Work In Progress	19,022	18,965
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(5,670)	(5,561)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	13,352	13,404
Unregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(1)	(1)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	6	6
Gross public utility property, plant and equipment in service	7	7
Electric Operations [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation or Processing	12,108	12,107
Public Utilities, Property, Plant and Equipment, Transmission	1,844	1,838
Public Utilities, Property, Plant and Equipment, Distribution	3,418	3,380
Natural Gas Processing Plant [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution	$ 1,652	$ 1,640