Business and Basis of Presentation (Detail)		3 Months Ended		12 Months Ended
	Nov. 18, 2019	Mar. 31, 2020 USD ($) $ / shares	Mar. 31, 2019 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Organization And Basis Of Presentation [Line Items]
Restructuring Charges				$ 2,300,000
Accounts receivable, net		$ 386,124		298,967
Net proceeds from issuance of stock and warrants		453,457	$ 0
Accumulated deficit		195,446,976		194,789,605
Cash and cash equivalents		2,816,485		3,126,206
Allowance for doubtful accounts		70,000		70,000
Reverse stock split conversion ratio	0.1
Prepaid expenses and other current assets		(340,369)		(652,919)
Assets, Current		(4,877,868)		(5,430,814)
Accrued Sales Return provisions		603,000		689,000
Liabilities, Current		(2,882,143)		(3,446,778)
Operating Lease, Liability, Noncurrent		(810,235)		(916,674)
Stockholders' Equity Attributable to Parent		2,514,118	8,192,411	2,530,234	$ 6,097,811
Cost of revenues		620,190	2,324,231
Gross Profit		1,551,846	798,704
Net Income (Loss) Available to Common Stockholders, Diluted		(657,371)	$ 2,050,507
Compensation cost not yet recognized		$ 408,144
Compensation cost not yet recognized, period for recognition		9 months 18 days
Earnings Per Share, Basic | $ / shares		$ (0.45)	$ 2.65
Earnings Per Share, Diluted | $ / shares		$ (0.45)	$ 1.47
Operating Lease, Right-of-Use Asset		$ (1,048,937)		(1,159,774)
Other long-term assets		(29,650)		(29,650)
Assets		(6,206,496)		(6,893,686)
Accrued Liabilities, Current		(1,064,580)		(1,443,574)
Liabilities		(3,692,378)		$ (4,363,452)
Collaboration Income		$ 0	$ 5,734,849
Two Customers | Revenue | Customer Concentration Risk
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage		36.00%	32.00%
Two Customers | Accounts Receivable | Customer Concentration Risk
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage				42.00%
Three Customers | Accounts Receivable | Customer Concentration Risk
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage		62.00%