License Agreement - Beijing (Details) - USD ($) $ in Thousands		3 Months Ended
	Jul. 23, 2019	Mar. 31, 2020
License Agreements
Minimum expected period to begin future installment payment		1 year
Maximum
License Agreements
Clinical supply agreement execution period from effective date		12 months
License Agreement with Beijing SL
License Agreements
Revenue recognized from the agreement		$ 0
Upfront payment to be received	$ 2,500	$ 2,500
Period from effective date within which upfront gross payment to be paid	45 days
Developmental and regulatory milestone payment eligible to be received	$ 6,000
Global net sales milestone payment to be received	$ 20,000
License Agreement with Beijing SL | Maximum
License Agreements
Percentage of royalty on net sales		20.00%