XML 53 R43.htm IDEA: XBRL DOCUMENT v3.10.0.1
Subsequent Event - Additional Information (Detail) - $ / shares
3 Months Ended 6 Months Ended
Nov. 15, 2018
Aug. 22, 2018
Oct. 31, 2018
Oct. 31, 2017
Oct. 31, 2018
Oct. 31, 2017
Subsequent Event [Line Items]            
Cash dividends declared per common share   $ 0.11 $ 0.11 $ 0.11 $ 0.22 $ 0.22
Cash dividend payable date         Dec. 05, 2018  
Cash dividends declared, record date         Nov. 19, 2018  
Subsequent Event            
Subsequent Event [Line Items]            
Cash dividends declared per common share $ 0.11          
Cash dividend payable date Feb. 22, 2019          
Cash dividends declared, record date Feb. 08, 2019