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Summary of Significant Accounting Policies (MEC) Utility Plant, Net - General (Details) (MidAmerican Energy Company [Member], USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Regulated electric [Member]
     
Notes to Financial Statements [Line Items]      
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service 3.30% 3.30% 3.20%
Regulated gas [Member]
     
Notes to Financial Statements [Line Items]      
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service 2.80% 2.80% 2.90%
Depreciable Assets [Member]
     
Notes to Financial Statements [Line Items]      
Change in Accounting Estimates, Impact on Period of Change $ 20   $ 16
Change in Accounting Estimates, Impact on Future Periods 49   28
Service Life [Member]
     
Notes to Financial Statements [Line Items]      
Change in Accounting Estimates, Impact on Period of Change   5  
Change in Accounting Estimates, Impact on Future Periods   $ 11