Government Contract Revenue - Narrative (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($) course	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Apr. 30, 2020 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment recognized as revenue	$ 24,861	$ 16,427
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-04-01
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Remaining performance obligations	$ 65,600
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-04-01
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Remaining performance obligations, expected recognize period	6 years
Minimum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-04-01
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Remaining performance obligations, expected recognize period	3 years
Government Contract Service Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment recognized as revenue	$ 2,172	973
Product Revenue, Net
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment recognized as revenue	19,918	13,207
Government Contract Grant Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment recognized as revenue	$ 2,099	1,613
BARDA Contract
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract term	5 years
Option to extend term	10 years
Maximum payment receivable in contract	$ 303,600
Term of base period of performance	5 years
Maximum number of years in contract period of performance	10 years
Maximum number of treatment courses procured | course	10,000
Initial award based on costs drawing down	$ 21,500
Potential additional staged funding for reimbursement of existing FDA PMR commitments	76,800			$ 31,600
Potential additional staged funding for reimbursement of manufacturing-related requirements	$ 20,400
Post-marketing bacterial surveillance study, period	5 years
Revenue performance obligations allocated transaction price	$ 63,600
Product revenue recognized			$ 37,900
Manufacturing-related requirements exercised				$ 31,600	$ 20,400
BARDA Contract | Accounts Receivable, Net
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Unbilled accounts receivable	900
BARDA Contract | Other Current Liabilities
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue	1,000	300
BARDA Contract | NUZYRA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Initial funding for development of NUZYRA	$ 59,400
Maximum number of treatment courses of drug product | course	2,500
Funding amount to procure ZUZYRA	$ 37,900
Funding for three additional purchases	$ 115,400
Maximum number of anthrax treatment courses procure options | course	2,500
Revenue performance obligations allocated transaction price	$ 4,200
BARDA Contract | NUZYRA | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
FDA approval period	24 months
BARDA Contract | NUZYRA | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
FDA approval period	18 months
BARDA Contract | Government Contract Service Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue performance obligations allocated transaction price	$ 21,500
Milestone payment recognized as revenue	2,200	1,000
BARDA Contract | Product Revenue, Net
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue performance obligations allocated transaction price	37,900
BARDA Contract | Government Contract Grant Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment recognized as revenue	2,100	$ 1,600
Allocated consideration for reimbursement of existing FDA PMR requirements related to reimbursable expenses	$ 72,600