Capital Stock - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended
	Jul. 29, 2016	Dec. 23, 2014	May 17, 2013	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Aug. 25, 2016	Dec. 31, 2014	Sep. 30, 2014	Aug. 09, 2013
Stockholders Equity [Line Items]
Convertible preferred stock, par value				$ 0.001
Convertible preferred stock, shares authorized				6,000,000
Common stock, shares authorized				450,000,000		450,000,000
Common stock, par value				$ 0.001		$ 0.001
Common Stock Shares Issued				229,435,726		229,381,059
Debt Conversion, Converted Instrument, Shares Issued				2,521,222
Interest Paid				$ 113,329	$ 113,750
Debt Conversion, Original Debt, Amount				14,316,255
May 2013 Private Placement [Member] | Minimum [Member]
Stockholders Equity [Line Items]
Common stock, shares authorized										150,000,000
May 2013 Private Placement [Member] | Maximum [Member]
Stockholders Equity [Line Items]
Common stock, shares authorized										300,000,000
Venture Loan [Member]
Stockholders Equity [Line Items]
Warrants exercise price per share		$ 0.1003
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		2,492,523
Proceeds from Issuance of Long-term Debt		$ 5,000,000
Interest Paid				106,000	113,000
Paid-in-Kind Interest				109,000	38,000
Debt Instrument, Unamortized Discount				$ 496,000
Debt Restructuring 2016 [Member]
Stockholders Equity [Line Items]
Debt Principal Amount Reduced Percentage				33.00%			33.00%			33.00%
Investor [Member]
Stockholders Equity [Line Items]
Sale of Stock, Consideration Received on Transaction	$ 5,600,000	$ 5,025,000
Warrants exercise price per share	$ 0.0994	$ 0.1003
Sale of Stock, Price Per Share	$ 0.0994	$ 0.1003
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	56,262,571	50,099,700
Warrants Expiration Term	7 years	7 years
Danforth Advisors [Member]
Stockholders Equity [Line Items]
Common stock, par value									$ 0.25
Warrants Fair Value Disclosure									$ 24,000
Common Stock Shares Issued									100,000
Common Stock [Member]
Stockholders Equity [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion				39,089,161
Common Stock [Member] | May 2013 Private Placement [Member]
Stockholders Equity [Line Items]
Sale of Stock, Consideration Received on Transaction			$ 12,000,000
Sale of Stock, Number of Shares Issued in Transaction			43,715,847
Sale of Stock, Price Per Share			$ 0.2745
Warrants 2013 [Member]
Stockholders Equity [Line Items]
Percentage Of Warrants Exercisable			63.00%
Percentage Of Warrants Exercisable After Shareholder Approval			37.00%
Warrants exercise price per share			$ 0.2745
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			32,786,885
Warrants 2014 [Member]
Stockholders Equity [Line Items]
Warrants Fair Value Disclosure		$ 261,000
Warrants and Rights Outstanding								$ 5,200,000
Warrants 2016 [Member]
Stockholders Equity [Line Items]
Warrants Fair Value Disclosure						$ 6,500,000
Lender Warrant 2016 [Member]
Stockholders Equity [Line Items]
Warrants exercise price per share				$ 0.0994
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				5,169,577
Warrants and Rights Outstanding						$ 504,000
Lender Warrant 2016 [Member] | Venture Loan [Member]
Stockholders Equity [Line Items]
Interest Paid				$ 106,000	$ 113,000
Placement Agent Warrants [Member]
Stockholders Equity [Line Items]
Allocated Share-based Compensation Expense				$ 780,000
Warrants To Purchase Of Common Stock				2,295,082
Warrants exercise price per share				$ 0.2745
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		89,731
Warrants and Rights Outstanding								$ 9,000
Payments for Underwriting Expense	$ 63,000	$ 218,000