Supplemental Cash Flow Disclosures - MEC (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,673	$ 1,764	$ 1,585
Income taxes received, net	[1]	1,016	1,666	635
Accruals related to property, plant and equipment additions		547	718	1,143
MidAmerican Energy Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		181	154	144
Income taxes received, net		601	629	149
Accruals related to property, plant and equipment additions		131	249	128
Dividend, Noncash, Transfer Of Operations		$ 90	$ 0	$ 0

[1] Includes $1.1 billion, $1.8 billion and $764 million of income taxes received from Berkshire Hathaway in 2016, 2015 and 2014, respectively.