Segment Information Segment Information - MidAmerican Funding (Details) $ in Millions		3 Months Ended
		Mar. 31, 2021 USD ($) ReportableSegments OperatingSegments	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | OperatingSegments		8
Operating revenue		$ 6,081	$ 4,527
Operating income		1,333	919
Interest expense		(530)	(483)
Allowance for borrowed funds		14	17
Allowance for equity funds		26	34
Other, net		8	(27)
Income before income tax (benefit) expense and equity income		(246)	507
Assets		$ 127,522		$ 127,316
MidAmerican Funding, LLC and Subsidiaries [Member]
Segment Reporting Information [Line Items]
Number of reportable segments | ReportableSegments		2
Operating revenue		$ 1,067	686
Operating income		48	102
Interest expense		(78)	(81)
Allowance for borrowed funds		2	3
Allowance for equity funds		6	8
Other, net		10	(6)
Income before income tax (benefit) expense and equity income		(12)	26
Assets	[1]	23,274		22,711
MidAmerican Funding, LLC and Subsidiaries [Member] | Electricity Us Regulated Member
Segment Reporting Information [Line Items]
Operating revenue		545	471
Operating income		9	59
Assets	[1]	21,463		21,083
MidAmerican Funding, LLC and Subsidiaries [Member] | Natural Gas US Regulated Member
Segment Reporting Information [Line Items]
Operating revenue		512	209
Operating income		39	39
Assets	[1]	1,804		1,623
MidAmerican Funding, LLC and Subsidiaries [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating revenue		10	6
Operating income		0	$ 4
Assets	[1]	$ 7		$ 5

[1] (1)    Consists principally of cash and cash equivalents not included in either the regulated electric or regulated natural gas segments.