Stockholders' Equity - Exchangeable Shares, Share Repurchase Program and Secondary Public Offering (Details) $ in Millions			12 Months Ended
	Jun. 13, 2019 shares	Jun. 01, 2018 shares	Apr. 30, 2022 USD ($) shares	Apr. 30, 2021 shares	Apr. 30, 2020 USD ($) shares
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (shares) | shares			715,000	0	134,000
Shares repurchased, cost | $			$ 35.5		$ 4.2
Remaining amount under repurchase program | $			18.8
Maximum
Equity, Class of Treasury Stock [Line Items]
Authorized amount of shares to be repurchased under the program | $			$ 75.0
Titan
Equity, Class of Treasury Stock [Line Items]
Issuance of shares to current shareholders of Titan (in shares) | shares		1,100,000
Exchangeable shares conversion ratio		1
Exchangeable shares converted (in shares) | shares	1,100,000