Development and License Agreements - Additional Information (Detail) € in Millions	1 Months Ended	3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 EUR (€)	Jun. 30, 2015 USD ($)	Dec. 31, 2016 EUR (€)	Jun. 30, 2016 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)
Licenses Agreements [Line Items]
Manufacturing and development obligations - current	$ 2,221,000	$ 2,221,000		$ 2,221,000					$ 3,282,000
Manufacturing and development obligations - non-current	4,844,000	4,844,000		4,844,000					4,542,000
Payments made relating to the manufacturing of the products		3,500,000	$ 4,700,000	7,000,000		$ 9,400,000
Amounts due from Fresenius	$ 900,000	900,000		900,000					200,000
BARDA Agreement
Licenses Agreements [Line Items]
Period of agreement	5 years
Contracts revenue		0	$ 0	0		$ 0
BARDA Agreement | Maximum | Base Period
Licenses Agreements [Line Items]
Committed fund receivable	$ 30,800,000	30,800,000		30,800,000
BARDA Agreement | Maximum | Option Period
Licenses Agreements [Line Items]
Committed fund receivable	180,500,000	180,500,000		180,500,000
Other current assets
Licenses Agreements [Line Items]
Research and development assets	3,300,000	3,300,000		3,300,000					4,100,000
Other assets
Licenses Agreements [Line Items]
Manufacturing efficiency assets	2,200,000	2,200,000		2,200,000					2,400,000
Fresenius
Licenses Agreements [Line Items]
Allocated amount for research and development activities	4,800,000	4,800,000		4,800,000
Manufacturing efficiency activity cost	2,400,000	2,400,000		2,400,000
Cerus Corporation | BARDA Agreement
Licenses Agreements [Line Items]
Co-investment by the company				14,500,000
Manufacturing and Supply Agreement
Licenses Agreements [Line Items]
Accrual for manufacturing of entity products	2,800,000	2,800,000		2,800,000					2,500,000
Manufacturing and Supply Agreement | Fresenius
Licenses Agreements [Line Items]
Accrual for manufacturing and development of entity products	7,000,000	7,000,000		$ 7,000,000				€ 6.4	7,800,000	€ 7.2
Manufacturing and development obligations, discount rate				9.72%	9.72%
Manufacturing and development obligations - current	2,200,000	2,200,000		$ 2,200,000				2.0	3,300,000	3.0
Manufacturing and development obligations - non-current	$ 4,800,000	$ 4,800,000		4,800,000				€ 4.4	$ 4,500,000	€ 4.2
Manufacturing and development payments				$ 1,200,000	€ 1.1
Scenario Forecast | Manufacturing and Supply Agreement | Fresenius
Licenses Agreements [Line Items]
Payments made based on the successful achievement of production volumes | €							€ 8.6