Fixed Assets (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Less accumulated depreciation and amortization	$ (6,656,000)	$ (6,065,000)
Less accumulated depreciation and amortization Fixed assets net	591,000
Fixed assets, net	4,157,000	4,748,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 6,075,000	6,075,000
Estimated useful lives	10 years
Manufacturing facility/ clean room
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 3,081,000	3,081,000
Manufacturing facility/ clean room | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Manufacturing facility/ clean room | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Lab equipment
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 1,137,000	1,137,000
Lab equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Lab equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 520,000	$ 520,000
Office furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Office furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years