Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Computation of basic and diluted earnings per share of common stock
Net income	$ 61,202	$ 27,219
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)	43,089,000	42,624,000
Basic earnings per common share (in dollars per share)	$ 1.42	$ 0.64
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)	43,089,000	42,624,000
Add: Common Stock Equivalents	883,000	393,000
Diluted weighted average common shares outstanding (in shares)	43,972,000	43,017,000
Diluted earnings per common share (in dollars per share)	$ 1.39	$ 0.63
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares (in shares)	0