XML 70 R47.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Schedule of Weighted-Average Fair Value and the Assumptions Used to Measure Fair Value (Details) - Restricted Stock Awards - $ / shares
3 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Weighted-average fair value (usd per share) $ 24 $ 20
Expected volatility (percent) 29.80% 30.50%
Risk-free interest rate (percent) 1.90% 1.40%
Expected performance period in years 2 years 10 months 24 days 2 years 10 months 24 days