Summary of Significant Accounting Policies - Reconciliation of Net Income/(Loss) Amounts and Weighted Average Number of Common and Common Equivalent Shares Used to Determine Basic and Diluted Earnings(Loss) per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Aug. 23, 2020	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Earnings Per Share [Abstract]
Basic (loss)/earnings		$ (64,880)	$ 18,405	$ (96,201)
Diluted (loss)/earnings		$ (64,880)	$ 18,405	$ (96,201)
Basic		13,930,000	13,997,000	13,975,000
Effect of dilutive stock awards, Shares			228,000
Diluted (loss)/earnings, Shares	0	13,930,000	14,225,000	13,975,000
Basic (loss)/earnings, Per Share Amount		$ (4.66)	$ 1.31	$ (6.88)
Effect of dilutive stock awards, Per Share Amount			(0.02)
Diluted (loss)/earnings, Per Share Amount		$ (4.66)	$ 1.29	$ (6.88)