Summary of Significant Accounting Policies - Cumulative Effect of Changes in Consolidated Balance Sheet for Adoption of Topic 606 (Detail) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
ASSETS
Inventories, net	$ 301,277	$ 171,514	$ 256,149
Prepaid expenses and other	784,720	656,464	695,276
Stockholders’ Equity:
Accumulated deficit	$ (48,011,033)	(45,412,973)	(45,289,526)
Adoption of ASC 606 [Member] | Balance [Member]
ASSETS
Inventories, net			256,149
Prepaid expenses and other			695,276
Stockholders’ Equity:
Accumulated deficit			$ (45,289,526)
Adoption of ASC 606 [Member] | Adjustments due to ASC 2014-09
ASSETS
Inventories, net		(84,635)
Prepaid expenses and other		(38,812)
Stockholders’ Equity:
Accumulated deficit		$ (123,447)