Earnings per share - Schedule Of Common Stock Shares Equivalent Excluded From Calculation Of Diluted Earnings Per Share (Details) - shares	3 Months Ended	6 Months Ended
Sep. 30, 2022	Sep. 30, 2022
Class B Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method
Antidilutive securities	82,021,389	82,021,389
Employee Stock Option [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method
Antidilutive securities	0	168,076

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 https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

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