Supplemental Cash Flow Disclosures - MEC (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,713	$ 1,715	$ 1,673
Income taxes received, net	[1]	780	540	1,016
Accruals related to property, plant and equipment additions		823	653	547
MidAmerican Energy Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		198	193	181
Income taxes received, net		494	465	601
Accruals related to property, plant and equipment additions		371	224	131
Dividend, Noncash, Transfer Of Operations		$ 0	$ 0	$ 90

[1] Includes $884 million, $636 million and $1.1 billion of income taxes received from Berkshire Hathaway in 2018, 2017 and 2016, respectively.