Stockholders' Equity - Exchangeable Shares, Share Repurchase Program and Secondary Public Offering (Details) - USD ($) shares in Thousands	6 Months Ended
Oct. 31, 2021	Oct. 31, 2020
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in shares)	280	50
Shares repurchased, cost	$ 13,100,000	$ 1,200,000
Remaining amount under repurchase program	41,200,000
Maximum
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount	$ 75,000,000

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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