Warrants - Additional Information (Details)					1 Months Ended	3 Months Ended		12 Months Ended
	May 05, 2020 USD ($) $ / shares shares	Feb. 22, 2019 USD ($) $ / shares shares	Feb. 15, 2019 shares	Mar. 06, 2017 $ / shares shares	Feb. 28, 2019 USD ($)	Jun. 30, 2020 USD ($) $ / shares shares	Mar. 31, 2019 shares	Dec. 31, 2019 USD ($) $ / shares
Right Offering [Member]
Class Of Warrant Or Right [Line Items]
Number of shares issued upon right offering | shares		5,976,000		1,706,000
Share price (in dollars per share)		$ 5.792		$ 11.76
Proceeds from issuance or sale of equity, total | $		$ 34,400,000			$ 34,400,000
Exercise price of exercisable warrant		$ 11.76
Underwriter warrants price per share		11.76
Additional share price (in dollars per share)		$ 11.76		$ 11.76
Term of warrants		5 years		5 years
Warrants to purchase shares of common stock | shares						632
Underwriter’s Warrants [Member]
Class Of Warrant Or Right [Line Items]
Percentage of underwriting fee and reimbursable expenses	8.50%
Underwriting fee and reimbursable expenses | $	$ 90,000
Other expenses | $	100,000
Cash consideration | $	$ 100
Purchase of common stock by underwriter granted | shares	375,000
Exercise price of exercisable warrant	$ 1.25
Warrants expiration date	Apr. 30, 2020
Underwriter warrants price per share	$ 1.25
Warrant [Member]
Class Of Warrant Or Right [Line Items]
Exercise price of exercisable warrant	$ 0.75					$ 11.27		$ 11.76
Issuance of shares of common stock and warrants in connection with rights offering, net of issuance costs (in shares) | shares	280,000
Underwriter warrants price per share	$ 0.75					$ 11.27		$ 11.76
Warrants exercisable, intrinsic value | $						$ 0
Warrant [Member] | Expected Lives [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input	5 years
Warrant [Member] | Risk Free Interest Rate [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input	94.0
Warrant [Member] | Expected Volatility [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input	0.67
Warrant [Member] | Dividend Yield [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input	0.0
March 2017 Warrants [Member]
Class Of Warrant Or Right [Line Items]
Number of warrants issued | shares			1.7
Adjustment to additional paid-in capital and accumulated deficit | $								$ 1,600,000
March 2017 Warrants [Member] | Right Offering [Member]
Class Of Warrant Or Right [Line Items]
Term of warrants			2 years
March 2017 Warrants Before Extension [Member] | Expected Lives [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			3 years 29 days
March 2017 Warrants Before Extension [Member] | Risk Free Interest Rate [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			2.50
March 2017 Warrants Before Extension [Member] | Expected Volatility [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			81
March 2017 Warrants Before Extension [Member] | Dividend Yield [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			0.00
March 2017 Warrants After Extension [Member] | Expected Lives [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			5 years 29 days
March 2017 Warrants After Extension [Member] | Risk Free Interest Rate [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			2.49
March 2017 Warrants After Extension [Member] | Expected Volatility [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			82
March 2017 Warrants After Extension [Member] | Dividend Yield [Member]
Class Of Warrant Or Right [Line Items]
Alternative investment, measurement input			0.00
Common Stock [Member]
Class Of Warrant Or Right [Line Items]
Number of shares issued upon right offering | shares	7,500,000
Share price (in dollars per share)	$ 1.00
Proceeds from issuance or sale of equity, total | $	$ 6,700,000
Issuance of shares of common stock and warrants in connection with rights offering, net of issuance costs (in shares) | shares						7,500,000	5,976,000