Convertible Preferred Stock and Stockholders Equity - Additional Information (Details)										3 Months Ended				9 Months Ended		12 Months Ended		24 Months Ended	36 Months Ended
	Aug. 10, 2020 shares	May 27, 2020 shares	Mar. 02, 2020 USD ($) shares	Feb. 28, 2020 USD ($) $ / shares shares	Sep. 24, 2019	Aug. 29, 2019 USD ($) shares	Jan. 04, 2019 USD ($)	Jun. 23, 2017 shares	Aug. 31, 2016 USD ($) $ / shares	Sep. 30, 2020 $ / shares shares	Jun. 30, 2020 shares	Mar. 31, 2020 shares	Sep. 30, 2019 USD ($) shares	Sep. 30, 2020 USD ($) Warrant $ / shares shares	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2018 $ / shares shares	Dec. 31, 2019 $ / shares shares	May 29, 2019 shares
Class of Stock [Line Items]
Common stock, shares authorized										50,000,000				50,000,000						50,000,000
Preferred stock, shares authorized										5,000,000				5,000,000
Common stock, par value per share | $ / shares										$ 0.0001				$ 0.0001						$ 0.0001
Preferred stock, par value per share | $ / shares										$ 0.0001				$ 0.0001
Business combination shares issued for each share of common stock														1.16
Conversion ratio of reverse stock split						0.5								0.5
Proceeds from issuance of Convertible Preferred Stock | $															$ 4,000,000
Preferred stock, issuance costs | $														$ 77,000
Common stock warrants issued																	102,740
Issuance of preferred stock, total offering amount | $													$ 718,000
Stock-based compensation expense recognized as a result of accelerated vesting | $							$ 400,000
Common stock available for issuance										7,612				7,612						4,787
2010 Stock Option Plan
Class of Stock [Line Items]
Common stock initially reserved for issuance										1,000,000				1,000,000
Contractual term of options granted														10 years
Options remain available for future grant										0				0						100,000
2010 Stock Option Plan | Incentive Stock Options
Class of Stock [Line Items]
Options granted to shareholder, percentage														10.00%
2020 Equity Incentive Plan
Class of Stock [Line Items]
Common stock, shares authorized										1,900,000				1,900,000
Contractual term of options granted														10 years
Options remain available for future grant										1,091,817				1,091,817
Common stock outstanding percentage														3.50%
2020 Employee Stock Purchase Plan
Class of Stock [Line Items]
Options remain available for future grant										400,000				400,000
Shares, issued										300,000				300,000
Common stock outstanding percentage														1.00%
Percentage of price at shares purchased														85.00%
Maximum | 2020 Equity Incentive Plan
Class of Stock [Line Items]
Shares, issued										1,400,000				1,400,000
Term of the option														5 years
Maximum | 2020 Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock available for issuance										400,000				400,000
Minimum | 2010 Stock Option Plan | Incentive and Non-statutory Stock Options
Class of Stock [Line Items]
Options granted, exercise price expressed as a percentage of fair market value														100.00%
Minimum | 2010 Stock Option Plan | Incentive Stock Options
Class of Stock [Line Items]
Options granted, exercise price expressed as a percentage of fair market value														110.00%
Minimum | 2020 Equity Incentive Plan | Incentive Stock Options
Class of Stock [Line Items]
Options granted, exercise price expressed as a percentage of fair market value														110.00%
Minimum | 2020 Equity Incentive Plan | Incentive and Non-qualified Stock Options
Class of Stock [Line Items]
Options granted, exercise price expressed as a percentage of fair market value														100.00%
Public Warrants
Class of Stock [Line Items]
Warrants issued to purchase common stock								14,936,250
Warrants expiration period										5 years				5 years
Number of warrants entitle holder to purchase one share | Warrant														4
Warrants outstanding										14,936,250				14,936,250						14,936,250
Series C Warrants
Class of Stock [Line Items]
Warrants expiration period										3 years				3 years
Warrants outstanding										106,416				106,416						202,897
Placement Agent Warrants
Class of Stock [Line Items]
Warrants issued to purchase common stock																		168,522	72,658
Warrants expiration period																7 years		7 years	7 years
Warrants outstanding																				241,217
Placement Agent Warrants | 2018 Convertible Bridge Notes
Class of Stock [Line Items]
Warrants issued to purchase common stock														15,724
Warrants expiration period										7 years				7 years
Warrants outstanding										251,349				251,349
Management Warrants
Class of Stock [Line Items]
Warrants expiration period										10 years				10 years
Warrants outstanding										22,320				22,320						22,320
Securities Purchase Agreement
Class of Stock [Line Items]
Preferred stock, issuance costs | $				$ 5,100,000
Gross proceeds from PIPE financing | $				$ 65,000,000
2020 PIPE Financing | Securities Purchase Agreement
Class of Stock [Line Items]
PIPE financing closing date														Mar. 04, 2020
Common Stock
Class of Stock [Line Items]
Preferred stock, shares issued during period													647,411
Issuance of common stock through conversion, Shares										1,139,199	3,198,949		1,524,122
Common Stock | Public Warrants
Class of Stock [Line Items]
Number of shares issued for each warrant										0.25				0.25
Exercise price of warrant | $ / shares										$ 23.00				$ 23.00
Common Stock | Series C Warrants
Class of Stock [Line Items]
Exercise price of warrant | $ / shares										$ 9.54				$ 9.54
Common Stock | Placement Agent Warrants
Class of Stock [Line Items]
Number of shares issued for each warrant																1		1	1
Exercise price of warrant | $ / shares																$ 9.54		$ 8.68	$ 9.54
Common Stock | Placement Agent Warrants | 2018 Convertible Bridge Notes
Class of Stock [Line Items]
Number of shares issued for each warrant										1				1
Exercise price of warrant | $ / shares										$ 9.54				$ 9.54
Common Stock | Management Warrants
Class of Stock [Line Items]
Exercise price of warrant | $ / shares										$ 1.08				$ 1.08
Warrants vesting period														4 years
Common Stock | 2020 PIPE Financing | Securities Purchase Agreement
Class of Stock [Line Items]
Issuance of preferred stock, price per share | $ / shares				$ 10.50
Issuance of stock				2,467,724
Issuance price per share | $ / shares				$ 10.50
Series C convertible preferred stock
Class of Stock [Line Items]
Issuance of preferred stock, total offering amount | $									$ 15,000,000
Issuance of preferred stock, price per share | $ / shares									$ 9.54
Preferred stock, shares issued during period																506,539	559,849
Proceeds from issuance of Convertible Preferred Stock | $																$ 4,800,000	$ 5,300,000
Preferred stock, issuance costs | $																$ 300,000	$ 400,000
Issuance of common stock through conversion, Shares													(1,524,122)
Issuance price per share | $ / shares									$ 9.54
Series C convertible preferred stock | Series C Warrants
Class of Stock [Line Items]
Percentage of warrants issued in connection with preferred stock purchased														20.00%
Series C convertible preferred stock | Series C Warrants | Minimum
Class of Stock [Line Items]
Preferred stock value of shares purchased in single closing | $														$ 1,000,000
Series C convertible preferred stock | Common Stock
Class of Stock [Line Items]
Series c convertible preferred stock convert into common stock shares, conversion ratio					1
Convertible preferred stock convertible into shares of common stock																					1
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized										0				0						1,250
Preferred stock, par value per share | $ / shares										$ 0.0001				$ 0.0001						$ 0.0001
Preferred stock, shares issued during period	1,231					1,231							1,231
Convertible preferred stock convertible into shares of common stock										500				500
Issuance of preferred stock, total offering amount | $						$ 4,000,000
Issuance of common stock through conversion, Shares	615,385									(1,231)
Convertible preferred stock convertible into shares of common stock, conversion price per share | $ / shares														$ 6.50
Event of convertible preferred stock be convertible if holder beneficially owning outstanding shares of common stock percentage														9.99%
Voting rights of preferred stock holder														The shares of the Series A Convertible Preferred Stock had no voting rights, except with respect to certain protective provisions set forth in the Series A Certificate of Designation relating to the powers, preferences and rights of such shares.
Convertible preferred stock, shares outstanding										0				0						1,231
Series B-1 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued during period												3,199
Proceeds from issuance of Convertible Preferred Stock | $														$ 30,968,000
Convertible preferred stock convertible into shares of common stock										1,000				1,000
Issuance of common stock through conversion, Shares											(3,199)
Convertible preferred stock convertible into shares of common stock, conversion price per share | $ / shares														$ 10.50
Voting rights of preferred stock holder														The Series B-1 Shares had no voting rights, except with respect to certain protective provisions set forth in the Series B-1 Certificate of Designation relating to the powers, preferences and rights of such shares.
Series B-1 Convertible Preferred Stock | 2020 PIPE Financing
Class of Stock [Line Items]
Preferred stock, shares issued during period			3,199
Issuance of preferred stock, total offering amount | $			$ 33,600,000
Issuance of common stock through conversion, Shares		3,198,949
Convertible preferred stock, shares outstanding		3,199
Series B-1 Convertible Preferred Stock | 2020 PIPE Financing | Securities Purchase Agreement
Class of Stock [Line Items]
Issuance of preferred stock, price per share | $ / shares				$ 10,500
Issuance of stock				3,199
Issuance price per share | $ / shares				$ 10,500
Preferred stock designated shares authorized and unissued				3,200
Series B-2 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued during period												524
Proceeds from issuance of Convertible Preferred Stock | $														$ 5,071,000
Convertible preferred stock convertible into shares of common stock										1,000				1,000
Issuance of common stock through conversion, Shares										(524)
Convertible preferred stock convertible into shares of common stock, conversion price per share | $ / shares														$ 10.50
Event of convertible preferred stock be convertible if holder beneficially owning outstanding shares of common stock percentage														9.99%
Voting rights of preferred stock holder														The Series B-2 Shares had no voting rights, except with respect to certain protective provisions set forth in the Series B-2 Certificate of Designation relating to the powers, preferences and rights of such shares.
Conversion of stock description														Each Series B-2 Share was convertible into Company common stock at the option of the holder, provided that conversion will be prohibited (i) until the first trading day after the Stockholder Approval, which occurred on May 27, 2020, and (ii) following the Stockholder Approval, if, as a result of any such conversion, the holder would beneficially own in excess of 9.99% of the total number of shares of Company common stock outstanding immediately after giving effect to such conversion (the “Beneficial Ownership Limitation”).
Series B-2 Convertible Preferred Stock | 2020 PIPE Financing
Class of Stock [Line Items]
Preferred stock, shares issued during period	524													524
Issuance of preferred stock, total offering amount | $														$ 5,500,000
Issuance of common stock through conversion, Shares	523,814
Series B-2 Convertible Preferred Stock | 2020 PIPE Financing | Securities Purchase Agreement
Class of Stock [Line Items]
Issuance of preferred stock, price per share | $ / shares				$ 10,500
Issuance of stock				524
Issuance price per share | $ / shares				$ 10,500
Preferred stock designated shares authorized and unissued				525