Convertible Instruments - Additional Information (Detail)

v3.20.2

Convertible Instruments - Additional Information (Detail)												1 Months Ended				3 Months Ended	12 Months Ended
	Jul. 30, 2020 USD ($) shares	Jul. 29, 2020 USD ($)	Mar. 13, 2020 USD ($) $ / shares shares	Jan. 31, 2020 USD ($) $ / shares shares	Jan. 28, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 16, 2019 USD ($)	Aug. 29, 2019 USD ($) shares	Mar. 20, 2019 USD ($) $ / shares shares	Jun. 26, 2018 USD ($) $ / shares	Jan. 31, 2018 USD ($) $ / shares shares	Apr. 30, 2020 USD ($) $ / shares shares	Apr. 16, 2019 USD ($)	Jan. 30, 2019 USD ($)	Nov. 15, 2018 USD ($) $ / shares	Nov. 30, 2019 USD ($) $ / shares shares	May 31, 2020 USD ($) $ / shares shares	May 31, 2019 USD ($) $ / shares shares	May 31, 2018 USD ($) $ / shares	May 31, 2010 USD ($) $ / shares shares	Jun. 29, 2020 shares	Jun. 16, 2020 $ / shares shares	Apr. 03, 2020 shares	Feb. 12, 2020 shares	Feb. 04, 2020 shares	Oct. 11, 2019 shares	Sep. 30, 2019 USD ($)	Apr. 30, 2010 shares
Class of Stock [Line Items]
Common stock, shares authorized | shares																	700,000,000	700,000,000
Convertible preferred stock, par value | $ / shares																	$ 0.001	$ 0.001
Convertible note, aggregate principal																	$ 15,000,000
Convertible notes, interest rate																	5.00%	10.00%
Common stock warrants to purchase shares | shares																									833,332
Exercise price of warrants, per share | $ / shares																$ 0.45
Amortization of debt discount																	$ 1,644,625	$ 1,707,068	$ 1,666,017
Amortization of debt issuance costs																	$ 404,340	459,085	435,609
Number of shares to be sold | shares																	3,756,406
Proceeds from sale of common stock and warrant																	$ 12,665,799	38,268,839	25,224,212
Repayment of note																	1,725,000
Proceeds from convertible promissory note														$ 5,000,000
Convertible promissory note maximum redemption amount																	950,000
Convertible note, redeemed amount																	4,476,000
Accrued dividends																	$ 981,438	$ 37,351
Preferred stock, shares authorized | shares																	5,000,000	5,000,000
Debt outstanding amount																	$ 0	$ 3,586,035
Notes Payable Repayment																	$ 1,725,000
Common Stock, Shares, Issued | shares																	519,261,580	329,554,763
Interest paid																$ 525,000	$ 242,817		$ 9,157
Subsequent Event
Class of Stock [Line Items]
Common stock warrants to purchase shares | shares																						105,000
Exercise price of warrants, per share | $ / shares																						$ 0.45
Common Stock, Shares, Issued | shares																					4,000,000
Investor Warrants
Class of Stock [Line Items]
Common stock warrants to purchase shares | shares																		5,460,000						1,666,668
Conversion of Preferred Stock to Common Stock
Class of Stock [Line Items]
Undeclared dividend																	245,000	$ 222,000
Accrued dividend																	$ 490,000	444,000
Short-Term Convertible Notes
Class of Stock [Line Items]
Conversion price | $ / shares																	$ 0.50		$ 0.75
Convertible note, aggregate principal																			$ 4,890,000
Convertible notes, interest rate																			7.00%
Common stock warrants to purchase shares | shares											7,718,010
Unamortized discount																	$ 0
Payment obligation against which common stock issued											$ 5,788,500
Accrued but unpaid interest											$ 243,000
Number of shares to be sold | shares											12,062,728
Sale of Stock, Price Per Share | $ / shares											$ 0.50
Proceeds from sale of common stock and warrant											$ 6,000,000
Repayment of note											259,000						250,000
Interest expense																	0	$ 0	$ 75,000
Net carrying value of note																	0
Debt outstanding amount																	5,788,500
Notes Payable Repayment											$ 259,000						250,000
Short-Term Convertible Notes | Investor Warrants
Class of Stock [Line Items]
Common stock warrants to purchase shares | shares																		4,025,656
Exercise price of warrants, per share | $ / shares																$ 0.30		$ 1.00
Unamortized discount																			1,600,000
Amortization of debt discount																		$ 0	1,600,000
Short-Term Convertible Notes | Detachable Common Stock Warrants
Class of Stock [Line Items]
Unamortized discount																	2,100,000	4,200,000	1,500,000
Amortization of debt discount																	$ 1,600,000	1,700,000	1,600,000
Unamortized issuance costs																			400,000
Amortization of debt issuance costs																		0	400,000
Note
Class of Stock [Line Items]
Convertible notes, interest rate										10.00%
Number of shares to be sold | shares																	8,512,622
Interest expense										$ 1,500,000							$ 383,000	386,000
Convertible promissory note principle amount		$ 28,500,000								5,700,000
Proceeds from convertible promissory note		$ 25,000,000								$ 5,000,000
Common stock conversion price | $ / shares										$ 0.55					$ 0.55
Convertible promissory note maximum redemption amount															$ 350,000
Convertible promissory note redemption description										The June 2018 Note provided for conversion in total, or in part, of the outstanding balance, into common stock of the Company at any time after six months from the issue date upon five trading days’ notice, subject to certain adjustments and ownership limitations specified in the June 2018 Note, and allowed for redemption, at any time after six months from the issue date upon five trading days’ notice, subject to a maximum monthly redemption amount of $350,000.					Effective November 15, 2018, the June 2018 Note was amended to allow the Investor to redeem the monthly redemption amount of $350,000 in cash or stock, at the lesser of (i) $0.55, or (ii) the lowest closing bid price of the Company’s common stock during the 20 days prior to the conversion, multiplied by a conversion factor of 85%.
Terms of conversion										1.5
Convertible note, redeemed amount																	1,455,000
Fair value of Note																		6,900,000
Net carrying value of note																		$ 5,400,000
2019 Short Term Convertible Notes
Class of Stock [Line Items]
Conversion price | $ / shares																		$ 0.50
Convertible note, aggregate principal																$ 200,000		$ 5,500,000									$ 200,000
Convertible notes, interest rate																		10.00%
Term of warrants																		5 years
Unamortized discount																	0	$ 1,469,625	0
Amortization of debt discount																	800,000
Unamortized issuance costs																	0	404,340	0
Amortization of debt issuance costs																		1,700,000
Payment obligation against which common stock issued																		$ 972,000
Sale of Stock, Price Per Share | $ / shares																		$ 0.50
Proceeds from sale of common stock and warrant																		$ 583,200
Repayment of note																700,000	460,000	0	0
Interest expense																	444,000	213,000	0
Common stock conversion price | $ / shares				$ 0.50		$ 0.50						$ 0.50
Outstanding balance of convertible note including accrued unpaid interest				$ 512,063		$ 549,912						$ 4,116,005
Net carrying value of note																	0	3,586,035	0
Debt outstanding amount																											5,900,000
Notes Payable Repayment																700,000	460,000	$ 0	$ 0
Noncash inducement interest expense																$ 300,000
Common Stock, Shares, Issued | shares				1,025,205		1,099,823						8,232,006
2019 Short Term Convertible Notes | Tranche One [Member]
Class of Stock [Line Items]
Debt outstanding amount																											1,100,000
2019 Short Term Convertible Notes | Investor Warrants
Class of Stock [Line Items]
Exercise price of warrants, per share | $ / shares																		$ 0.30
Term of warrants																		5 years
2019 Short Term Convertible Notes | Detachable Common Stock Warrants
Class of Stock [Line Items]
Amortization of debt discount																	$ 3,000,000
2019 Short Term Convertible Notes | Conversion of Preferred Stock to Common Stock
Class of Stock [Line Items]
Amortization of debt issuance costs																		$ 500,000
January 2019 Note [Member]
Class of Stock [Line Items]
Convertible notes, interest rate																		10.00%
Common stock warrants to purchase shares | shares																		5,000,000
Exercise price of warrants, per share | $ / shares																		$ 0.30
Term of warrants																	5 years
Unamortized discount																	$ 5,760,000	$ 600,000
Unamortized issuance costs																		100,000
Number of shares to be sold | shares																	10,842,255
Interest expense																	$ 6,145,000	$ 126,000
Convertible promissory note principle amount														$ 5,700,000
Proceeds from convertible promissory note																	$ 5,000,000
Common stock conversion price | $ / shares																	$ 0.50
Convertible promissory note redemption description																	The January 2019 Note provided the investor may redeem any portion of the January 2019 Note upon five trading days’ notice, subject to a maximum monthly redemption amount of $350,000. The monthly redemption amount may be paid in cash or stock, at the Company’s election, at the lesser of (i) $0.50, or (ii) the lowest closing bid price of the Company’s common stock during the 20 days prior to the conversion, multiplied by a conversion factor of 85%.
Convertible note, redeemed amount							$ 350,000
Company Reserves Shares For Future Conversition | shares																	20,000,000
Interest paid																	$ 850,000
Convertible Promissory Notes [Member]
Class of Stock [Line Items]
Number of common shares issued upon conversion of preferred stock | shares																							1,000,000
Convertible note, aggregate principal																	$ 17,100,000
Convertible notes, interest rate																	10.00%
Common stock warrants to purchase shares | shares																4,750,000
Unamortized discount																	$ 1,925,000
Amortization of debt discount																	2,100,000
Proceeds from sale of common stock and warrant																	15,000,000
Interest expense																	$ 175,000
Common stock conversion price | $ / shares																	$ 4.50
Preferred Stock, Dividend Rate, Percentage																	15.00%
Common Stock
Class of Stock [Line Items]
Conversion price | $ / shares																		$ 0.50
Series B Convertible Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Share issuance price | $ / shares																				$ 5.00
Cash proceeds																				$ 2,009,000
Series B Convertible preferred stock, shares outstanding | shares																	92,100	92,100
Common stock, shares authorized | shares																												100,000,000
Constructive dividend to Preferred stock holders																	$ 6,000,000
Liquidation preference on common shares | $ / shares																	$ 5.00
Dividends are payable to preferred stock holders | $ / shares																	0.25
Convertible preferred stock, par value | $ / shares																	$ 0.001	$ 0.001		$ 0.001
Preferred stock, shares authorized | shares																	400,000	400,000
Preferred stock, shares issued | shares																		92,100		400,000
Series B Convertible Preferred Stock | Subsequent Event
Class of Stock [Line Items]
Series B Convertible preferred stock, shares outstanding | shares	87,100
Number of common shares issued upon conversion of preferred stock | shares	5,000
Dividends are payable to preferred stock holders	$ 243,285
Series C Convertible Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Share issuance price | $ / shares																	$ 1,000.00
Cash proceeds								$ 1,542,545	$ 3,083,700
Series B Convertible preferred stock, shares outstanding | shares								1,754									8,203	3,246
Common stock, shares authorized | shares									5,000
Convertible preferred stock, par value | $ / shares									$ 0.001								$ 0.001	$ 0.001
Placement agent fee								$ 211,455					$ 162,300
Preferred Stock, Dividend Rate, Percentage																	10.00%
Convertible Preferred Stock Conversion Price | $ / shares																	$ 0.50
Accrued dividends																	$ 709,000
Accrued dividend Shares | shares																	1,419,000
Preferred stock, shares authorized | shares																	8,203	8,203								20,000
Preferred stock, shares issued | shares									3,246								8,203	3,246								2,788
Series C Convertible Preferred Stock | 2019 Short Term Convertible Notes | Tranche Two [Member]
Class of Stock [Line Items]
Debt outstanding amount																											$ 4,100,000
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Share issuance price | $ / shares			$ 1,000.00		$ 1,000.00												$ 1,000.00
Cash proceeds			$ 882,000		$ 7,565,000
Series B Convertible preferred stock, shares outstanding | shares																	8,452	0
Dividends are payable to preferred stock holders | $ / shares					$ 0.50
Convertible preferred stock, par value | $ / shares					$ 0.001												$ 0.001	$ 0.001
Placement agent fee					$ 5,000
Preferred Stock, Dividend Rate, Percentage					10.00%
Convertible Preferred Stock Conversion Price | $ / shares					$ 0.80
Accrued dividends																	$ 272,000
Accrued dividend Shares | shares																	544,000
Preferred stock, shares authorized | shares					11,737												11,737	11,737
Preferred stock, shares issued | shares			882		7,570												8,452	0