Basis of Presentation and Principles of Combination and Consolidation -Basis of Presentation (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
General and administrative expenses allocated from iStar	$ 14.1	$ 10.9
Interest expense allocated from iStar	8.0	42.0
General and Administrative
Stock-based compensation expense allocated from iStar	$ 1.8	$ (11.8)

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line allocated from iStar.

No definition available.

Name:	stho_GeneralAndAdministrativeExpenseAllocated
Namespace Prefix:	stho_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration