Liability Related to the Sales of Future Revenue (Details) - USD ($) $ in Millions	Sep. 30, 2025	Oct. 21, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liability related to the sale of future revenue	$ 15.0	$ 15.0

Liabilities Related To Sale Of Future Revenue, Noncurrent

No definition available.

Name:	twst_LiabilitiesRelatedToSaleOfFutureRevenueNoncurrent
Namespace Prefix:	twst_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant