Reconciliation of Weighted Average Shares Outstanding (Details) - shares shares in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Reconciliation of Weighted Average Shares Outstanding [Abstract]
Weighted average shares outstanding (in shares)	55,931	56,224	57,240
Less: Unvested restricted shares (in shares)	(1)	(15)	(48)
Shares used for basic earnings (loss) per share (in shares)	55,930	56,209	57,192
Dilutive effect of unvested restricted stock units and other stock awards (in shares)	531	0	648
Shares used for diluted earnings (loss) per share (in shares)	56,461	56,209	57,840
Options [Member]
Reconciliation of Weighted Average Shares Outstanding and Share Repurchases [Abstract]
Antidilutive options to purchase Class A common shares, restricted shares, warrants to purchase Class A common shares and contingently issuable restricted stock which are excluded from the table above (in shares)	982	1,677	958