Fixed Assets (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Less accumulated depreciation and amortization	$ (5,118,000)	$ (4,793,000)
Fixed assets, net	5,677,632	5,997,582
Manufacturing Facility/ clean room [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 3,082,000	3,076,000
Manufacturing Facility/ clean room [Member] | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Manufacturing Facility/ clean room [Member] | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 6,075,000	6,075,000
Estimated useful lives	10 years
Office Furniture And Equipment [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 511,000	511,000
Office Furniture And Equipment [Member] | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Office Furniture And Equipment [Member] | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 1,128,000	$ 1,128,000
Lab Equipment [Member] | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Lab Equipment [Member] | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years