v2.4.0.6
Additional Working Capital Information (Narrative) (Details) (USD $)
In Billions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Additional Working Capital Information [Abstract]    
Unused credit lines for short-term financing $ 5.5  
Commercial paper programs under terms negotiated $ 2.8  
The weighted-average interest rate on short-term borrowings outstanding 1.90% 1.20%