Development and License Agreements - Additional Information (Detail) € in Millions	1 Months Ended		3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2020 USD ($)	Aug. 31, 2019 EUR (€)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 EUR (€)	Sep. 30, 2019 USD ($)	Dec. 31, 2016 EUR (€)	Apr. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Licenses Agreements [Line Items]
Payments made relating to the manufacturing of the products			$ 8,000,000.0	$ 9,800,000	$ 22,500,000		$ 23,300,000
BARDA Agreement
Licenses Agreements [Line Items]
Additional committed fund receivable									$ 13,800,000
Committed fund receivable	$ 116,900,000		116,900,000		116,900,000
Committed fund receivable	213,900,000		213,900,000		213,900,000
Accounts receivable of billed and unbilled amounts	$ 4,100,000		$ 4,100,000		4,100,000					$ 4,200,000
FDA Agreement
Licenses Agreements [Line Items]
Contract agreement term	5 years
Total potential contract value	$ 11,100,000
Cerus Corporation \| BARDA Agreement
Licenses Agreements [Line Items]
Co-investment by the company					5,000,000.0
Additional co-investment by the company					9,600,000
Co-investment incurred by the company					$ 1,900,000
Manufacturing and Supply Agreement \| Fresenius
Licenses Agreements [Line Items]
Payments made based on the successful achievement of production volumes \| €						€ 8.6
Manufacturing and development payments \| €		€ 5.5						€ 3.1