Supplemental Cash Flow Disclosures - MEC (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Income Statements, Captions [Line Items]
Cash and cash equivalents		$ 1,040	$ 627
Restricted Cash and Cash Equivalents, Current		212	227
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		1,268	883	$ 1,283	$ 1,003
Interest paid, net of amounts capitalized		1,723	1,713	1,715
Income taxes received, net	[1]	850	780	540
Accruals related to property, plant and equipment additions		888	823	653
MidAmerican Energy Company [Member]
Condensed Income Statements, Captions [Line Items]
Cash and cash equivalents		287	0
Restricted Cash and Cash Equivalents, Current		43	56
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		330	56	282	$ 26
Interest paid, net of amounts capitalized		224	198	193
Income taxes received, net		450	494	465
Accruals related to property, plant and equipment additions		$ 337	$ 371	$ 224

[1] Includes $942 million, $884 million and $636 million of income taxes received from Berkshire Hathaway in 2019, 2018 and 2017, respectively.