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Income Taxes - MEC (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]    
Federal statutory income tax rate 35.00% 35.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Percent 14.00% 11.00%
State income tax, net of federal income tax benefit (4.00%) 2.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent 0.00% 2.00%
Effective income tax rate 14.00% 22.00%
Production Tax Credit Carryforwards [Abstract]    
Years eligible for federal renewable energy production tax credit 10 years  
MidAmerican Energy Company [Member]    
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]    
Federal statutory income tax rate 35.00% 35.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Percent 57.00% 63.00%
State income tax, net of federal income tax benefit 5.00% 4.00%
Effective Income Tax Rate Reconciliation Regulatory Differences 12.00% 11.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent 0.00% 1.00%
Effective income tax rate (29.00%) (36.00%)
Production Tax Credit Carryforwards [Abstract]    
Years eligible for federal renewable energy production tax credit 10 years  
MidAmerican Energy Company [Member] | Berkshire Hathaway Energy [Member]    
Related Party Income Tax Receivable (Payable) [Abstract]    
Related party transaction, cash received for income taxes, net $ 4 $ 0