Balance Sheet Details - Summary of Prepaid Expenses and Other Assets (Parenthetical) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Other prepaids and current assets, related parties, current	$ 0	$ 28

Other prepaids and current assets related parties current.

No definition available.

Name:	thor_OtherPrepaidsAndCurrentAssetsRelatedPartiesCurrent
Namespace Prefix:	thor_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant