|**Short Term Debt Instruments (Tables)**     | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|-------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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|**Line of Credit Facility [Abstract]**       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Schedule of Line of Credit Facilities        | We did not have any borrowings under the revolving syndicated credit facility for theninemonths endedJuly 31, 2016. A summary of the short-term debt activity under our CP program for thethree months and ninemonths endedJuly 31, 2016is as follows.In millionsThree MonthsNine MonthsMinimum amount outstanding during period$240$240Maximum amount outstanding during period$530$530Minimum interest rate during period.52%.20%Maximum interest rate during period.68%.75%Weighted average interest rate during period.60%.54%
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|                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|In millions                                  | Three Months                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Minimum amount outstanding during period     | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Maximum amount outstanding during period     | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Minimum interest rate during period          | .52                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Maximum interest rate during period          | .68                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Weighted average interest rate during period | .60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

X- ReferencesNo definition available.
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duration X- DefinitionTabular disclosure of short-term or long-term contractual arrangements with lenders, including letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line.
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