License and Other Agreements - Amendment to License Agreement with Yale (Details) - Yale Agreement - Collaborative arrangement - USD ($) $ in Thousands	1 Months Ended
	May 31, 2019	Sep. 30, 2013
License and other agreements
Common stock issued (shares)		250,000
Right to purchase securities in specified future equity offering (as a percent)		10.00%
Milestone payment to be paid upon regulatory achievement	$ 2,000
Minimum annual royalty payment to be paid upon sale of product	$ 1,000
Notice period to terminate agreement	90 days
Maximum
License and other agreements
Extension of due diligence requirements (in years)	1 year
Amount of payment subject to due diligence extension	$ 150