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Stock-Based Compensation - Weighted-Average Fair Value and Assumptions Used to Measure Fair Value of Stock Options (Details) - Stock Options - $ / shares
12 Months Ended
Oct. 31, 2019
Oct. 31, 2018
Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average fair value (in dollars per share) $ 3 $ 5 $ 4
Expected volatility (as a percent) 29.80% 29.40% 28.00%
Risk-free interest rate (as a percent) 1.70% 2.50% 1.90%
Expected dividend yield (percent) 3.70% 2.60% 2.80%
Expected performance period 6 years 5 years 5 years 6 months
Historical volatility 50.00%    
Implied volatility 50.00%