Share-based compensation - Share-based award activity (Details) - shares	Jun. 28, 2024	Jun. 30, 2023	Jun. 24, 2022	Jun. 25, 2021	Dec. 12, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,857,415
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,746,068				1,700,000
2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	111,347
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	306,660	368,765	459,626	641,875
Restricted Share Units | 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	306,660
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	285,882	427,028
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