v3.2.0.727
Derivative Instruments (Textuals) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Derivatives, Fair Value [Line Items]          
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax $ 0 $ 0 $ 0 $ 0  
Derivative Instruments (Textuals) [Abstract]          
Maximum length of time hedging using interest rate derivative instruments     8 years    
Derivative, Net Liability Position, Aggregate Fair Value 12   $ 12    
Collateral Already Posted, Aggregate Fair Value 9   9    
Additional Collateral, Aggregate Fair Value 14   14    
(Gain) Loss on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net   $ 5   $ 10  
Cash Flow Hedge (Gain) Loss to be Reclassified within Twelve Months     46    
Parent [Member]          
Derivatives, Fair Value [Line Items]          
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax 142   142   $ 149
Noncontrolling Interest [Member]          
Derivatives, Fair Value [Line Items]          
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax $ 11   $ 11   $ 12