Deferred Revenue - Additional Information (Details) - USD ($)							3 Months Ended		11 Months Ended
	Sep. 30, 2018	Sep. 19, 2018	Sep. 22, 2015	Jul. 20, 2015	Sep. 17, 2014	Dec. 17, 2013	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Apr. 17, 2018
Deferred Revenue Arrangement [Line Items]
Proceeds from funding agreement				$ 250,000	$ 500,000	$ 250,000
Interest in asset				0.50%	1.00%	0.50%
Number of shares issuable term				60 days	60 days	60 days
Number of shares issuable (in shares)				25,000	62,500	31,250
Recognized as revenue							$ 1,655,000
Number of shares per dollar exchange rate (in shares)			0.1
Grants receivable										$ 7,400,000
Grant revenue							1,575,000		$ 2,600,000
BARDA
Deferred Revenue Arrangement [Line Items]
Proceeds from funding agreement	$ 611,000
Period of funding for remaining balance		2 years
Plan | BARDA
Deferred Revenue Arrangement [Line Items]
Proceeds from funding agreement		$ 4,600,000
Research and Development Arrangement December 17, 2013
Deferred Revenue Arrangement [Line Items]
Recognized as revenue							14,400	$ 14,400
Research and Development Arrangement September 17, 2014
Deferred Revenue Arrangement [Line Items]
Recognized as revenue							39,200.0	39,200.0
Research and Development Arrangement July 20, 2015
Deferred Revenue Arrangement [Line Items]
Recognized as revenue							$ 26,800	0
Research And Development Arrangement September 19, 2018
Deferred Revenue Arrangement [Line Items]
Recognized as revenue								$ 34,329