Balance Sheet Details - Summary of Accrued Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Accrued research and development, related parties, current	$ 233	$ 59
Other accrued liabilities, related parties, current	$ 41	$ 64

Accrued research and development related parties current.

No definition available.

Name:	thor_AccruedResearchAndDevelopmentRelatedPartiesCurrent
Namespace Prefix:	thor_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant