Supplemental Cash Flow Disclosures - MidAmerican Funding (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,764	$ 1,585	$ 1,073
Income taxes received, net	[1]	1,666	635	1,105
Accruals related to property, plant and equipment additions		718	1,143	661
MidAmerican Funding, LLC and Subsidiaries [Domain]
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		177	167	132
Income taxes received, net		630	153	42
Accruals related to property, plant and equipment additions		$ 249	$ 128	$ 117

[1] Includes $1.8 billion, $764 million and $1.2 billion of income taxes received from Berkshire Hathaway in 2015, 2014 and 2013, respectively.