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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, 2020
Oct. 31, 2019
Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average fair value (in dollars per share) $ 3 $ 3 $ 5
Expected volatility (as a percent) 29.80% 29.80% 29.40%
Risk-free interest rate (as a percent) 1.60% 1.70% 2.50%
Expected dividend yield (percent) 4.00% 3.70% 2.60%
Expected performance period 6 years 6 years 5 years
Historical volatility 50.00%    
Implied volatility 50.00%