Financing Arrangement (Convertible Note Hedge and Warrants Issuance) (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified
1 Months Ended
Jul. 31, 2011
Jul. 14, 2011
Convertible Note Hedge [Member]    
Financing Arrangement [Line Items]    
Shares covered by warrants issuance   19.9
Amount paid for Convertible Note Hedge $ 107  
Warrant [Member]    
Financing Arrangement [Line Items]    
Shares covered by warrants issuance   19.9
Strike price of warrants   41.14
Proceeds from Warrants transaction $ 65  
Convertible Debt    
Financing Arrangement [Line Items]    
Debt Instrument, Convertible, Conversion Price   31.74