Takeda Agreements - Narrative (Details)	May 30, 2018	Apr. 29, 2016
Supply Commitment [Line Items]
Period for which royalties are required to be paid after first commercial sale		10 years
Takeda Agreements
Supply Commitment [Line Items]
Initial agreement term	5 years
Renewal term	1 year
Termination notice period	12 months
Termination notice period, uncured material breach	90 days
Term notice period, open purchase orders filled	180 days