Commitments - Supply Agreement (Details)		6 Months Ended
	Jun. 22, 2017 USD ($) day	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
License agreement
Other Commitments [Line Items]
Upfront payments	2
Percent of upfront payments which may be paid by issuing common stock	50.00%
Percent of average share price	75.00%
Threshold trading days | day	20
Maximum additional product milestone payments	$ 1,800,000
Maximum additional commercialization milestone payments	$ 5,000,000.0
Termination advance notice period	30 days
Other commitment		$ 250,000
Agreement expense		$ 0	$ 225,000
Supply agreement
Other Commitments [Line Items]
Other commitment, period	20 years
Material cure period	60 days