License and Collaboration Agreements (Details) - License and collaboration agreement with Zai Lab - USD ($)	1 Months Ended	3 Months Ended		24 Months Ended
	Apr. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020
License and Collaboration Agreement with Zai Lab
Upfront, non-refundable payment received	$ 5,000,000			$ 5,000,000
Research support funding				600,000
Certain other reimbursable registration trial costs				2,000,000
Payment received, tax expense				2,000,000
Eligible amount receivable in research and development support payments and development, regulatory and sales milestone payments		$ 91,000,000		91,000,000
Revenue		$ 0	$ 0	$ 7,000,000