Debt - Additional Information (Details) - USD ($)				12 Months Ended
	Sep. 28, 2017	May 11, 2017	Aug. 04, 2016	Dec. 31, 2017	Jan. 13, 2017
Line Of Credit Facility [Line Items]
Maximum borrowing capacity			$ 35,000,000
Credit facility repayment term, description				The loan repayment included interest (no principal) through August 2018 and was set to transition to principal and interest as of August 2018 and to be repaid in full on February 1, 2021 (54 months).
Credit facility repayment period			54 months
Maturity date of credit agreement			Feb. 01, 2021
Credit agreement reference rate for the variable rate				LIBOR
Credit agreement basis spread on variable rate			7.60%
Cash funding committed by Emergent in connection with spin-off					$ 20,000,000
Unamortized debt issuance costs				$ 1,400,000
Credit agreement exit fee, percentage			5.75%
Credit agreement final principal payment, percentage		6.75%
Credit agreement minimum cash threshold required amount		$ 25,000,000
Line of Credit
Line Of Credit Facility [Line Items]
Debt issuance costs				$ 1,900,000
Credit Facility First Tranche
Line Of Credit Facility [Line Items]
Maximum borrowing capacity			$ 20,000,000
Credit Facility Second Tranche
Line Of Credit Facility [Line Items]
Maximum borrowing capacity			15,000,000
Net commercial product revenue required to be achieved on trailing twelve month basis	$ 16,000,000		$ 40,000,000
Maximum borrowing capacity withdrawal date of tranche		2018-03	2017-08
Terminated maximum borrowing capacity	$ 15,000,000
Term loans extended amortization date based on net commercial product revenues recognized	Feb. 01, 2019
Net commercial product revenue, date to be achieved	Jun. 30, 2018
Net commercial product revenue requirements to be maintained				The date on which the term loans begin to amortize will be extended to February 1, 2019 if the Company achieves net commercial product revenues of $16 million for the twelve month period ending June 30, 2018 and maintains such level of net commercial product revenues for each quarter prior to February 1, 2019 thereafter.
Credit Facility Second Tranche | Minimum
Line Of Credit Facility [Line Items]
Unrestricted cash balance	$ 10,000,000