Inventories (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Inventory [Line Items]
Purchased components	$ 532,952	$ 532,952		$ 1,767,674
Inventory Write-down	0	(2,595,884)	$ 0
Finished goods	545,701	545,701		1,094,190
Inventories	$ 1,078,653	$ 1,078,653		$ 2,861,864