Government Contracts - Additional Information (Detail)		1 Months Ended			3 Months Ended
	Jul. 01, 2019 USD ($)	Oct. 31, 2022 USD ($)	May 31, 2021 USD ($) Option	Jul. 31, 2018 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jan. 19, 2022 USD ($)	Jan. 31, 2020 USD ($)	May 31, 2019 USD ($)
Government Contracts [Line Items]
Grant revenue					$ 2,069,000	$ 2,069,000
BARDA and DTRA [Member]
Government Contracts [Line Items]
Maximum potential funding from government contract					69,700,000
Potential grant amount exercised					12,700,000
Grant [Member] | DoD, CDMRP and JWMRP [Member] | Minimum [Member]
Government Contracts [Line Items]
Grant revenue					0	900,000
SPR206 [Member] | DoD, CDMRP and JWMRP [Member]
Government Contracts [Line Items]
Award received for clinical development	$ 5,900,000
Non-dilutive funding period	4 years
BARDA [Member]
Government Contracts [Line Items]
Potential contract amount awarded				$ 44,200,000					$ 59,700,000
Potential amount additional funding awarded									12,900,000
Overall potential award increased									$ 46,900,000
Award received for clinical development								$ 12,900,000
BARDA [Member] | Base Period Contracts [Member]
Government Contracts [Line Items]
Potential amount initial funding awarded				$ 15,700,000
Potential amount additional funding awarded											$ 2,500,000
Overall potential award increased											46,800,000
Contract term				3 years
BARDA [Member] | Base Period Contracts [Member] | Maximum [Member]
Government Contracts [Line Items]
Potential amount initial funding awarded											18,200,000
BARDA [Member] | Base Period Contracts [Member] | Minimum [Member]
Government Contracts [Line Items]
Potential amount initial funding awarded											$ 15,700,000
BARDA [Member] | Grant [Member]
Government Contracts [Line Items]
Grant revenue					500,000	700,000
BARDA [Member] | First Option [Member]
Government Contracts [Line Items]
Potential amount additional funding awarded										$ 15,900,000
Potential amount increase in committed funding										$ 34,000,000.0
BARDA [Member] | Second Option [member]
Government Contracts [Line Items]
Potential grant amount awarded					12,700,000
DTRA [Member] | Maximum [Member]
Government Contracts [Line Items]
Potential amount additional funding awarded					10,000,000.0
Niaid [Member]
Government Contracts [Line Items]
Potential amount additional funding awarded							$ 100,000
Niaid [Member] | SPR206 [Member]
Government Contracts [Line Items]
Contract term			5 years
Potential amount increase in committed funding					6,200,000
Maximum potential funding from government contract							23,500,000
Grant revenue					$ 900,000	$ 300,000
Award received for clinical development			$ 23,400,000
Number of option period for funding from government contract | Option			5
Niaid [Member] | SPR206 [Member] | Maximum [Member]
Government Contracts [Line Items]
Potential amount increase in committed funding							2,200,000
Niaid [Member] | SPR206 [Member] | Minimum [Member]
Government Contracts [Line Items]
Potential amount increase in committed funding							$ 2,100,000
Niaid [Member] | First Option [Member] | SPR206 [Member]
Government Contracts [Line Items]
Committed amount from government contract		$ 4,000,000.0