Organization, Basis of Presentation and Liquidity - Additional Information (Detail)		3 Months Ended
	Apr. 13, 2018 USD ($)	Mar. 31, 2018 USD ($) Segment	Mar. 12, 2018	Dec. 31, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Income Tax Expense Benefit [Line Items]
Number of operating segment | Segment		1
Accumulated deficit		$ (459,972,000)		$ (455,170,000)
Working capital deficit		1,500,000
Shareholders' deficit		(16,713,000)		(12,531,000)
Cash position		1,395,000		$ 7,095,000	$ 17,214,000	$ 22,591,000
Ownership percentage			67.00%
Aggregate principal amount		$ 23,000,000
Grifols and First Eagle [Member]
Income Tax Expense Benefit [Line Items]
Ownership percentage		67.00%
Promissory Note [Member]
Income Tax Expense Benefit [Line Items]
Proceed from promissory notes issued		$ 2,000,000
Remaining amount of notes		$ 5,000,000
Subsequent Event [Member]
Income Tax Expense Benefit [Line Items]
Ownership percentage	67.00%
Subsequent Event [Member] | Grifols and First Eagle [Member]
Income Tax Expense Benefit [Line Items]
Ownership percentage	67.00%
Subsequent Event [Member] | Bridge Notes [Member] | Grifols and First Eagle [Member]
Income Tax Expense Benefit [Line Items]
Aggregate principal amount	$ 7,000,000
Subsequent Event [Member] | Promissory Note [Member]
Income Tax Expense Benefit [Line Items]
Proceed from promissory notes issued	2,000,000
Remaining amount of notes	$ 5,000,000