Declaration of Dividend Payable (Details) - $ / shares		3 Months Ended		6 Months Ended
	Aug. 21, 2019	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Dividends [Abstract]
Cash dividends payable, declared date	Aug. 21, 2019
Cash dividends declared per common share (in usd per share)	$ 0.11	$ 0.11	$ 0.11	$ 0.22	$ 0.22
Cash dividend payable date	Dec. 06, 2019
Cash dividends declared, record date	Nov. 22, 2019