Common Stock Warrants and Common Stock Warrant Liability (Details Textual) - USD ($) $ / shares in Units, $ in Thousands								1 Months Ended							3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 24, 2020	Dec. 03, 2019	Jul. 31, 2019	Aug. 13, 2018	Nov. 21, 2017	Jun. 15, 2015	Mar. 31, 2020	Mar. 04, 2020	Jan. 31, 2020	Jan. 31, 2020	Jan. 28, 2020	Jun. 30, 2018	Jun. 20, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued																	2,504,597
Share price (in dollars per share)												$ 7.90			$ 2.00		$ 2.00		$ 11.00
Change in fair value of the derivative warrant liability															$ 3	$ 2	$ 18	$ (3)
Warrants, description																	The initial exercise price of these warrants was $30.00 per share, which adjusted downward to $29.40 on July 24, 2018, the record date of the Right's Offering, downward to $19.00 per share on August 13, 2018, the date of the Rights Offering, downward to $7.13 per share on January 28, 2020, the date of a Registered Direct Offering and downward to $2.1122 per share on March 6, 2020, the date of a Registered Direct Offering.
Stock compensation expense																	$ 291	$ 471
Deemed dividend																	$ 285
Weighted-average exercise price																	$ 6.18
Right Offering [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued					267,853
Exercise price (in dollars per share)					$ 23.00
Share price (in dollars per share)					$ 23.00
Fair value of common stock warrant					$ 3,600
Number of share issued in transaction					267,853
Right Offering [Member] | Common Stock Purchase Warrants [Member] | Maxim Partners LLC [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued					13,393
Exercise price (in dollars per share)					$ 34.50
Share price (in dollars per share)					$ 18.80
Fair value of common stock warrant					$ 169
Expected volatility rate					159.00%
Expected term					5 years
Expected dividend rate					0.00%
Risk free interest rate					2.77%
Right Offering [Member] | Common Stock Purchase Warrants [Member] | Monte Carlo Model [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued					267,853
Share price (in dollars per share)					$ 18.80
Expected volatility rate					159.00%
Expected term					5 years
Expected dividend rate					0.00%
Risk free interest rate					2.77%
Public Offering [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased						293,000
Common Stock warrants issued [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued														56,696
Number of warrant purchased						232,875									56,696		56,696
Exercise price (in dollars per share)						$ 30.00									$ 36.40		$ 36.40
Warrant term						5 years
Description of method used						Lattice model
Share price (in dollars per share)						$ 26.80								$ 42.20
Fair value of common stock warrant						$ 661
Expected volatility rate						73.80%							72.60%	72.60%
Expected term						5 years							5 years	5 years
Expected dividend rate						0.00%							0.00%
Risk free interest rate						1.87%							2.80%
Proceeds from warrant exercises													$ 1,700	$ 1,700
Stock compensation expense													1,700
Deemed Dividend Adjustment-Warrant Modified Terms Revaluation [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Exercise price (in dollars per share)															12.00		$ 12.00
Expected volatility rate																	73.20%
Expected term																	4 days
Expected dividend rate																	0.00%
Risk free interest rate																	1.63%
Warrants, description			The Company agreed to modify the terms of 6,934 common stock warrants that were originally issued to New Enterprises between September 2015 and February 2016. Specifically, the original strike price was reduced to $20.00 per warrant from $150.00 per warrant and the expiration date of these warrants was extended one year to December 13, 2020.
Deemed dividend																	$ 11
Unexercised warrants																	$ 6,934
Deemed Dividend Adjustment-Warrant Modified Terms Revaluation [Member] | Warrants [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued																	51,414
Cashless exercise																	56,625
Exercise price (in dollars per share)															12.00		$ 12.00
Expected volatility rate																	73.20%
Expected term																	1 year 4 days
Expected dividend rate																	0.00%
Risk free interest rate																	1.63%
Settlement outstanding litigation reserve																	$ 238
University of Arizona Common Stock Warrant [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Warrant term																	5 years
Description of method used																	Monte Carlo model based
University of Arizona Common Stock Warrant [Member] | License Agreement [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased							750
Exercise price (in dollars per share)							$ 150.00
Change in fair value of the derivative warrant liability							$ 53
Common Stock Warrant Issued to Underwriter of Common Stock Offering [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Exercise price (in dollars per share)					$ 19.00				$ 2.1122			$ 7.13
Share price (in dollars per share)									$ 2.88
Expected volatility rate									74.50%			73.80%
Expected term									2 years 8 months 16 days			2 years 9 months 25 days
Expected dividend rate									0.00%			0.00%
Risk free interest rate									0.68%			1.45%
Deemed dividend									$ 129
Unexercised warrants									$ 143,501
Common Stock Warrant Issued to Underwriter of Common Stock Offering [Member] | H.C. Wainwright & Co [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased				8,334
Exercise price (in dollars per share)				$ 33.75											33.75		$ 33.75
Warrant term				5 years
Share price (in dollars per share)															$ 1		$ 1
Fair value of common stock warrant															$ 127		$ 127
Expected volatility rate																	133.30%
Expected term																	5 years
Expected dividend rate																	0.00%
Risk free interest rate																	2.07%
New Warrants November 8, 2017 [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased														56,696
Exercise price (in dollars per share)														$ 36.40
Proceeds from warrant exercises													$ 513
New Warrants November 8, 2017 [Member] | Common Stock Purchase Warrants [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased														17,088
Common Stock Warrants Issued in January and March 2020 Private Placements [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued										177,500							353,872
Number of warrant purchased								176,372
Exercise price (in dollars per share)								$ 2.88		$ 9.00	$ 9.00
Description of method used								The Company estimated the fair value of the common stock warrants, exercisable at $2.88 per share, to be $242 using a Black Scholes model based on the following significant inputs: common stock price of $2.35		The Company estimated the fair value of the common stock warrants, exercisable at $9.00 per share, to be $813 using a Black Scholes model based on the following significant inputs: common stock price of $7.90
Expected volatility rate								74.80%		73.80%
Expected term								5 years 6 months		5 years
Expected dividend rate								0.00%		1.53%
Risk free interest rate								0.39%
Expire date, description										Exercisable after July 28, 2020 and will expire July 28, 2025.							Expire September 8, 2025.
Fundamental Transaction, description																	Any acquisition of our outstanding common stock that results in any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding common stock
Limitations on Exercise, description																	A holder (together with its affiliates) may not exercise any portion of the 2020 Warrants to the extent that the holder would own more than 4.99% of the outstanding common stock after exercise (the "Beneficial Ownership Limitation"), except that upon at least 61 days' prior notice from the holder to us, the holder may increase the Beneficial Ownership Limitation up to 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the 2020 Warrants.
Common Stock Warrants Issued to Placement Agent in 2020 Registered Direct Offerings and Private Placement [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued																	13,228
Exercise price (in dollars per share)															$ 10.00		$ 10.00
Description of method used	The Company estimated the fair value of the common stock warrants issued in April, with an exercise price of $3.97 per share, to be $167 using a Black Scholes model based on the following significant inputs: common stock price of $2.40							The Company estimated the fair value of the common stock warrants issued in March, with an exercise price of $3.7563 per share, to be $17 using a Black Scholes model based on the following significant inputs: common stock price of $2.35			The Company estimated the fair value of the common stock warrants issued in January, with an exercise price of $10.00 per share, to be $58 using a Black Scholes model based on the following significant inputs: common stock price of $7.90
Expected volatility rate	87.90%							74.80%			73.80%
Expected term	5 years 6 months							5 years 6 months			5 years
Expected dividend rate	0.00%							0.00%			0.00%
Risk free interest rate	0.18%							0.39%			1.53%
Common Stock Warrants Issued to Placement Agent in 2020 Registered Direct Offerings and Private Placement [Member] | Wainwright & Co., LLC [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued																	13,313
Number of warrant purchased		118,073
Exercise price (in dollars per share)		$ 3.97													$ 3.7563		$ 3.7563
Common Stock Warrants Issued to Placement Agent in 2020 Registered Direct Offerings and Private Placement [Member] | Wainwright & Co., LLC [Member] | Common Class A [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued		145,586
Common Stock Warrants Issued to Placement Agent in 2020 Registered Direct Offerings and Private Placement [Member] | Wainwright & Co., LLC [Member] | Common Class B [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued		1,428,722
Common Stock Warrants Issued in April 2020 Public Offering
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Number of warrant purchased		1,574,308
Exercise price (in dollars per share)		$ 3.05
Description of method used																	The Company estimated the fair value of the common stock warrants, exercisable at $3.05 per share, to be $2,402 using a Black Scholes model based on the following significant inputs: common stock price of $2.40
Expected volatility rate																	87.90%
Expected term																	5 years
Expected dividend rate																	0.00%
Risk free interest rate																	0.18%
Warrant expire		Apr. 24, 2025
Common Stock Warrants Issued in April 2020 Public Offering | Common Class A [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued		145,586
Common Stock Warrants Issued in April 2020 Public Offering | Common Class B [Member]
Common Stock Warrants and Common Stock Warrant Liability (Textual)
Common Stock Offering Warrants Issued		1,428,722