Warranties (Details) (USD $)
In Millions
6 Months Ended
Apr. 30, 2011
Apr. 30, 2010
Warranties [Abstract]    
Warranty terms Our warranty terms typically extend for one year from the date of delivery  
Summary of standard warranty accrual activity [Rollforward]    
Beginning balance $ 45 $ 28
Accruals for warranties issued during the period 33 26
Changes in estimates 3 (2)
Settlements made during the period (32) (24)
Ending balance $ 49 $ 28