Commitments and contingencies - Future lease payments under operating and financing lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Operating leases
2021	$ 873
2022	586
2023	596
2024	605
2025	614
Thereafter	2,791
Total lease payments	6,065
Less: interest	1,455
Total lease liabilities	4,610	$ 4,363
Financing lease
2021	2,411
2022	2,483
2023	2,558
2024	2,634
2025	2,714
Thereafter	43,685
Total lease payments	56,485
Less: interest	29,107
Total lease liabilities	27,378
Total
2021	3,284
2022	3,069
2023	3,154
2024	3,239
2025	3,328
Thereafter	46,476
Total lease payments	62,550
Less: interest	30,562
Total lease liabilities	$ 31,988