Share-based compensation - Share-based award activity (Details) - shares	Mar. 29, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 24, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,865,252
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,753,905
2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	111,347
Restricted share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	311,565	368,765	374,038	459,626
Restricted share units | 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	311,565
Restricted share units | 2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	0
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	171,078	204,016	204,016	285,882
Performance share units | 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	171,078
Performance share units | 2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	0