Segment Information - LLC (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) operatingSegment reportableSegment	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | operatingSegment			8
Operating revenue	$ 6,064	$ 4,612	$ 12,145	$ 9,139
Operating income	1,208	936	2,541	1,855
Interest expense	(532)	(503)	(1,062)	(986)
Allowance for equity funds	30	38	56	72
Other, net	48	52	56	25
Income (loss) before income tax expense (benefit) and equity income (loss)	2,760	1,145	2,514	1,652
Assets	130,561		$ 130,561		$ 127,316
MidAmerican Funding, LLC
Segment Reporting Information [Line Items]
Number of reportable segments | reportableSegment			2
Operating revenue	693	616	$ 1,760	1,302
Operating income	103	110	151	212
Interest expense	(78)	(78)	(156)	(159)
Allowance for borrowed funds	2	4	4	7
Allowance for equity funds	8	9	14	17
Other, net	16	21	26	15
Income (loss) before income tax expense (benefit) and equity income (loss)	51	66	39	92
Assets	23,331		23,331		22,711
MidAmerican Funding, LLC | Electric
Segment Reporting Information [Line Items]
Operating revenue	586	518	1,131	989
Operating income	103	101	112	160
Assets	21,540		21,540		21,083
MidAmerican Funding, LLC | Natural Gas
Segment Reporting Information [Line Items]
Operating revenue	106	95	618	304
Operating income	0	7	39	46
Assets	1,787		1,787		1,623
MidAmerican Funding, LLC | Other
Segment Reporting Information [Line Items]
Operating revenue	1	3	11	9
Operating income	0	$ 2	0	$ 6
Assets	$ 4		$ 4		$ 5