Fair value measurements - Transfers between levels (Details) - USD ($)	12 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Fair value measurements
Fair value liabilities, transfer from level 1 to level 2	$ 0
Fair value liabilities, transfer from level 2 to level 1	0
Fair value liabilities, transfers from level 3	$ 0	$ 0

Amount of transfers of financial instrument classified as a liability into (out of) level 3 of the fair value hierarchy.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration