Business and Basis of Presentation (Detail)			1 Months Ended	3 Months Ended			6 Months Ended	12 Months Ended
	Jul. 12, 2017 USD ($)	May 12, 2017	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Organization And Basis Of Presentation [Line Items]
Accumulated deficit					$ 184,948,997		$ 184,948,997	$ 178,478,801
Cash and cash equivalents					3,611,949		3,611,949	3,949,135	$ 11,330,857	$ 12,462,872
Value of shipments made but not yet sold					2,031,262		2,031,262	1,247,545
Reduction to accounts receivable					1,371,989		1,371,989	619,309
Deferred revenue					659,273		659,273	628,236
Deferred costs of goods sold					1,276,207		1,276,207	910,595
Provision for expected returns recorded as accrued expense							413,871	488,200
Allowance for doubtful accounts					$ 25,000		$ 25,000	$ 25,000
Reverse stock split conversion ratio		0.125
Minimum
Organization And Basis Of Presentation [Line Items]
Product sales right of return term							30 days
Maximum
Organization And Basis Of Presentation [Line Items]
Product sales right of return term							60 days
2017 Offering
Organization And Basis Of Presentation [Line Items]
Gross proceeds from issuance of equity						$ 7,000,000
Net proceeds from issuance of stock and warrants						$ 6,300,000
Customer Concentration Risk | One Customer | Revenue
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage					16.00%		16.00%
Customer Concentration Risk | Second Customer | Revenue
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage					11.00%		12.00%
Customer Concentration Risk | Two Customers | Accounts Receivable
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage								41.00%
Customer Concentration Risk | Three Customers | Accounts Receivable
Organization And Basis Of Presentation [Line Items]
Concentration risk, percentage							58.00%
Subsequent Event | July 2017 Offering
Organization And Basis Of Presentation [Line Items]
Gross proceeds from issuance of equity	$ 3,500,000
Scenario, Forecast | July 2017 Offering
Organization And Basis Of Presentation [Line Items]
Gross proceeds from issuance of equity			$ 3,500,000
Scenario, Forecast | Subsequent Event | July 2017 Offering
Organization And Basis Of Presentation [Line Items]
Gross proceeds from issuance of equity				$ 7,000,000