XML 51 R39.htm IDEA: XBRL DOCUMENT v3.21.1
Significant Accounting Policies - Additional Information (Detail) - shares
3 Months Ended 6 Months Ended
Apr. 30, 2021
Apr. 30, 2020
Apr. 30, 2021
Apr. 30, 2020
Significant Accounting Policies [Line Items]        
Ownership percentage in affiliates and joint ventures 25.00%   25.00%  
Stock Options        
Significant Accounting Policies [Line Items]        
Options for common shares excluded from computation of diluted earning per share 91,000 360,000 91,000 180,000