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Income Taxes - MEC (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]        
Federal statutory income tax rate 35.00% 35.00% 35.00% 35.00%
Income tax credits (19.00%) (12.00%) (17.00%) (13.00%)
State income tax, net of federal income tax benefit 1.00% 1.00% (2.00%) (1.00%)
Other, net (0.00%) (1.00%) (1.00%) (1.00%)
Effective income tax rate 13.00% 19.00% 11.00% 17.00%
Production Tax Credit Carryforwards [Abstract]        
Years eligible for federal renewable energy production tax credit     10 years  
Related Party Income Tax Receivable (Payable) [Abstract]        
Related party transaction, cash received for income taxes, net       $ 658
MidAmerican Energy Company [Member]        
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]        
Federal statutory income tax rate 35.00% 35.00% 35.00% 35.00%
Income tax credits (67.00%) (60.00%) (73.00%) (59.00%)
State income tax, net of federal income tax benefit (4.00%) (5.00%) (2.00%) (1.00%)
Effects of ratemaking (5.00%) (2.00%) (7.00%) (6.00%)
Effective income tax rate (41.00%) (32.00%) (47.00%) (31.00%)
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     $ 7 $ 308