Shareholders' Equity - Additional Information (Details) - USD ($)				1 Months Ended					3 Months Ended			6 Months Ended	12 Months Ended
	Mar. 11, 2016	Apr. 22, 2013	Apr. 18, 2013	Feb. 28, 2015	Oct. 31, 2012	Jan. 31, 2012	Feb. 28, 2011	May. 31, 2010	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Jun. 30, 2014	Dec. 31, 2011	Dec. 31, 2010	Jan. 19, 2016	May. 16, 2015	Dec. 31, 2014	Sep. 30, 2013	Feb. 28, 2005
Class Of Stock [Line Items]
Proceeds from the common stock private placement				$ 14,500,000
Sale of common stock and warrants (in shares)				26,650,000
Exercise price of warrants (in USD per share)				$ 1.44		$ 1.87			$ 0.65	$ 1.79	$ 1.84	$ 1.85					$ 1.79
Common stock and warrants issued for cash per share (in USD per share)				$ 0.60
Common stock aggregate offering price									$ 9,173	$ 9,031
Commission rate			3.00%
Percentage of fair market value of common stock									not be less than 100%
Percentage of fair market value of common stock (in percent)									100.00%
Percentage of common stock voting rights held									more than 10%
Percentage of common stock voting rights held (in percent)									10.00%
Minimum percentage of fair market value of common stock									less than 110%
Minimum percentage of fair market value of common stock (in percent)									110.00%
Maximum exercisable period of options									10 years
Common stock, shares authorized under the plan (in shares)																		12,000,000	6,000,000
Stock granted during period (in shares)									260,000
Common stock reserved for issuance (in shares)	10,000,000
Common stock, shares granted and outstanding (in shares)									11,801,904	10,719,904
Unrecognized compensation cost related to unvested stock options									$ 1,800,000
Weighted-average remaining requisite service period									15 months
Options issued by the company (in shares)	1,082,000								1,082,000
Shares issued (in USD per share)	$ 0.33
Warrants exercisable period after initial issuance						5 years	5 years	5 years
Number of warrants outstanding increased net of exercises (in shares)				3,666,836						2,949,845	2,869,696	2,854,196
Warrants to purchase common stock (in shares)					2,823,670				3,666,836								2,949,867
Initial valuation of warrants									$ 2,476,790
Warrant liability carrying value									1,492,400	$ 1,958,775	$ 3,122,077						$ 597,719
Valuation of warrants				$ 4,197,375
Common stock authorized for sale															$ 15,081,494
Stock offering, maximum public float															$ 75,000,000
Proceeds from the issuance of common stock									264,668		0
Recovery of deferred offering costs									48,977
Financing expense									$ 14,636		88,939
February 2011
Class Of Stock [Line Items]
Proceeds from the common stock private placement							$ 2,476,790
Other Income											634,910
February 2011 | Warranty Obligations
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)							$ 2.25
February 2011 | Binomial Simulation | Scenario, Previously Reported
Class Of Stock [Line Items]
Dividend yield rate													0.00%
Expected volatility rate													146.00%
Risk-free interest rate													1.96%
Contractual life													5 years
January
Class Of Stock [Line Items]
Warrants to purchase common stock (in shares)									1,418,575
October
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)					$ 2.65
Warrants exercisable period after initial issuance					5 years
Warrants to purchase common stock (in shares)									4,446,775
February 2015
Class Of Stock [Line Items]
Warrants exercisable period after initial issuance				5 years
Warrants to purchase common stock (in shares)									18,655,000
Dividend yield rate				0.00%					0.00%
Expected volatility rate				97.00%					89.00%
Risk-free interest rate				1.53%					1.02%
Contractual life				5 years					3 years 10 months 8 days
Other Income									$ 481,011		1,119,300
Warrant liability carrying value									$ 1,492,400
Board of Directors
Class Of Stock [Line Items]
Stock granted during period (in shares)									40,000
Qualified Incentive Stock Options Granted Owning More Than Ten Percentage Of Combined Voting Power
Class Of Stock [Line Items]
Maximum exercisable period of options									5 years
Stock Compensation Plan
Class Of Stock [Line Items]
Common stock, shares granted and outstanding (in shares)									4,636,479
Restricted Stock Units (RSUs)
Class Of Stock [Line Items]
Stock granted during period (in shares)	314,500
Stock options, vesting period	2 years
Employee Stock Option
Class Of Stock [Line Items]
Stock options, vesting period	4 years
Maximum | February 2011
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)							$ 1.55
Cantor Fitzgerald And Company | Maximum
Class Of Stock [Line Items]
Common stock aggregate offering price			$ 25,000,000
Cantor Fitzgerald And Company | Offer and Sale
Class Of Stock [Line Items]
Common stock aggregate offering price			$ 17,000,000
Private Placement
Class Of Stock [Line Items]
Purchase of common stock (in shares)				18,655,000	4,500,000	4,744,718
Private Placement | Warranty Obligations
Class Of Stock [Line Items]
Purchase of common stock (in shares)							2,818,675
Public Offering
Class Of Stock [Line Items]
Common stock issued (in shares)		10,593,220
2015 Underwritten Public Offering
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)				$ 0.66
Common Stock
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)				$ 0.66		$ 1.41			$ 0.29	$ 0.36
Common stock issued (in shares)									1,417,648
Warrant
Class Of Stock [Line Items]
Warrant exercise term investor relations agreement				60 months
Warrant | February 2011
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)							$ 2.25
Warrant | Private Placement
Class Of Stock [Line Items]
Purchase of common stock (in shares)							2,818,675
Preferred Stock
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)								$ 2.50
Proceeds from issuance of warrants								$ 5,710,500
Preferred Stock | May
Class Of Stock [Line Items]
Exercise price of warrants (in USD per share)								$ 2.50								$ 2.50
Common stock warrants expired (in shares)																1,290,996
Other Income											$ 7,746
Preferred Stock | May | Binomial Simulation
Class Of Stock [Line Items]
Dividend yield rate														0.00%
Expected volatility rate														102.00%
Risk-free interest rate														2.50%
Contractual life														60 months
Preferred Stock | Private Placement
Class Of Stock [Line Items]
Purchase of common stock (in shares)								1,350,000