Segment Information - LLC (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) reportableSegment operatingSegment	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | operatingSegment			8
Operating revenue	$ 6,968	$ 6,193	$ 19,113	$ 15,332
Operating income	1,834	1,547	4,375	3,402
Interest expense	(531)	(504)	(1,593)	(1,490)
Allowance for equity funds	34	50	90	122
Other, net	8	36	64	61
Income (loss) before income tax expense (benefit) and equity income (loss)	1,675	2,967	4,189	4,619
Assets	131,554		$ 131,554		$ 127,316
MidAmerican Funding, LLC
Segment Reporting Information [Line Items]
Number of reportable segments | reportableSegment			2
Operating revenue	966	812	$ 2,726	2,114
Operating income	287	232	438	444
Interest expense	(81)	(79)	(237)	(238)
Allowance for borrowed funds	4	5	8	12
Allowance for equity funds	11	16	25	33
Other, net	8	15	34	30
Income (loss) before income tax expense (benefit) and equity income (loss)	229	189	268	281
Assets	24,218		24,218		22,711
MidAmerican Funding, LLC | Regulated electric
Segment Reporting Information [Line Items]
Operating revenue	854	728	1,985	1,717
Operating income	289	238	401	398
Assets	22,254		22,254		21,083
MidAmerican Funding, LLC | Regulated natural gas
Segment Reporting Information [Line Items]
Operating revenue	110	80	728	384
Operating income	(2)	(6)	37	40
Assets	1,953		1,953		1,623
MidAmerican Funding, LLC | Other
Segment Reporting Information [Line Items]
Operating revenue	2	4	13	13
Operating income	0	$ 0	0	$ 6
Assets	$ 11		$ 11		$ 5