v2.4.0.6
Fair Value Measurements (Narrative) (Details) (USD $)
In Billions, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Dec. 31, 2011
Interest Rate Swaps [Member]
     
Derivatives, Fair Value [Line Items]      
Fair value of interest rate swaps $ 0.6   $ 0.6
Notional amount of interest rate swaps 7.0    
Cross Currency Swaps [Member]
     
Derivatives, Fair Value [Line Items]      
Proceeds from other debt 1.6    
Fair value of cross currency swaps designated as cash flow hedges 0.1   0.1
Pre-tax gain (loss) recognized in other comprehensive income $ 0.1 $ 0.1