General and significant accounting policies (Narrative) (Details)	Sep. 30, 2024	Dec. 31, 2023	Jul. 01, 2023
Huatai Group
General and significant accounting policies [Line Items]
Subsidiary, Ownership Percentage, Parent	85.50%	76.50%	69.60%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant