v2.4.0.8
Derivative Instruments (Textuals) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Derivatives, Fair Value [Line Items]          
(Gain) Loss On Interest Rate Derivative Instruments Not Designated As Hedging Instruments, Unrealized       $ 14  
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net   0   2  
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax 7 3 4 7  
Derivative Instruments (Textuals) [Abstract]          
Maximum length of time hedging using interest rate derivative instruments     10 years    
Derivative, Net Liability Position, Aggregate Fair Value 10   10    
Collateral Already Posted, Aggregate Fair Value 1   1    
Additional Collateral, Aggregate Fair Value 0   0    
Cumulative cash flow hedge losses remaining in AOCI     173   242
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net 7   7,000,000    
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months     43    
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments 0 0 0 (14)  
Interest Rate Derivative Liabilities, Fair Value on Settlement Date [Line Items]          
(Gain) Loss on Interest Rate Derivative Instruments Not Designated as Hedging Instruments, realized       142  
Interest Rate Swap [Member]
         
Derivative Instruments (Textuals) [Abstract]          
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments       $ 156