XML 62 R44.htm IDEA: XBRL DOCUMENT v3.19.2
Allowance for Doubtful Accounts (Details) - USD ($)
$ in Millions
Apr. 30, 2019
Apr. 30, 2018
Allowance for Doubtful Accounts [Abstract]    
Allowance for Doubtful Accounts Receivable, Current $ 7 $ 7