Earnings Per Common Share - Additional Information (Details)	3 Months Ended	9 Months Ended
Jan. 31, 2021 shares	Jan. 31, 2020 shares	Jan. 31, 2021 $ / shares shares	Jan. 31, 2020 shares
Earnings Per Share [Line Items]
Share conversion ratio			1
Options to purchase excluded (in shares)	775,087	26,000	1,669,870	278,116
Options to purchase outstanding (in shares)	4,405,329	3,998,128	4,405,329	3,998,128
Class A Common Shares
Earnings Per Share [Line Items]
Dividends preference (in usd per share) \| $ / shares			$ 0.05

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration