Common Stock (Summary of Company’s sales under the Equity Distribution Agreement) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Class of Stock [Line Items]
Gross Proceeds	$ 682,000	$ 0
Net Proceeds	$ 436,000
Equity Distribution Agreement
Class of Stock [Line Items]
Total shares of common stock sold	1,241,000
Average price per share	$ 0.58
Gross Proceeds	$ 682,000
Commissions earned by placement agent	(27,000)
Legal/Audit fees	$ (219,000)