License and Collaboration Agreements - Summary of Revenue Recognized as a Result of Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2019
License And Collaboration Agreements [Abstract]
Amounts included in deferred revenue at the beginning of the period	$ 1,750	$ 3,500

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

No definition available.

Name:	us-gaap_DeferredRevenueRevenueRecognized1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration