Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total debt, Principal	$ 19,499
Less: debt - current, Principal	(5,056)	$ (3,050)
Less: debt - current, Unamortized Discount	87	94
Less: debt-current	(4,969)	(2,956)
Debt - non-current, Principal	14,443	16,950
Debt - non-current, Unamortized Discount	(61)	(102)
Debt-non-current	14,382	16,848
Cerus Term Loans
Debt Instrument [Line Items]
Total debt, Principal	19,499	20,000
Total debt, Unamortized Discount	(148)	(196)
Total debt	$ 19,351	$ 19,804