Annual report pursuant to Section 13 and 15(d)

Convertible Preferred Stock and Warrants (Details)

Convertible Preferred Stock and Warrants (Details) $ / shares in Units, $ in Millions		12 Months Ended
	Apr. 09, 2019 USD ($) Agreement $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Nov. 30, 2019 shares	Dec. 31, 2018 shares
Class Of Stock [Line Items]
Number of underwriting agreements \| Agreement	2
Aggregate gross proceeds from public offerings \| $	$ 70.0
Underwriting discounts and commissions and estimated offering expenses payable \| $	$ 5.0
Preferred stock, shares outstanding		0		0
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Share price (in dollars per share) \| $ / shares		$ 6.57
Preferred stock, shares outstanding		0	666
Convertible preferred stock beneficial conversion feature \| $		$ 0.6
Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock		2,118,344
Warrant exercise price of common stock per share \| $ / shares		$ 8.625
Warrants exercisable date		Oct. 10, 2022
Maximum ownership percentage to total number stock issued and outstanding holder is prohibited from conversion		4.99%
Notice period for change in owning percentage		61 days
Warrants outstanding and remain unexercised		2,118,094
Change fair value of warrants \| $		$ 9.0
Class A Warrants \| Weighted Average Volatility \| Weighted Average
Class Of Stock [Line Items]
Fair value of weighted average volatility		86.06%
Class A Warrants \| Weighted Average Expected Term \| Weighted Average
Class Of Stock [Line Items]
Fair value of weighted expected term		3 years 6 months
Common Stock \| Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of series A stock into common stock			666,000
Public Offering \| Class A Warrants
Class Of Stock [Line Items]
Warrant exercise price of common stock per share \| $ / shares	$ 8.625
Warrants exercisable date	Oct. 10, 2022
Public Offering \| Common Stock Agreement \| Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock	1,951,844
Share price (in dollars per share) \| $ / shares	$ 7.50	$ 7.50
Public Offering \| Common Stock Agreement \| Common Stock
Class Of Stock [Line Items]
Shares issued	8,667,333
Public Offering \| Preferred Stock Agreement \| Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Shares issued	666
Public Offering \| Preferred Stock Agreement \| Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock	166,500
Share price (in dollars per share) \| $ / shares	$ 7,500