Common Stock - Additional Information (Detail)					1 Months Ended				3 Months Ended		12 Months Ended
	Feb. 19, 2020 $ / shares	Feb. 13, 2020 shares	Jul. 16, 2018 $ / shares shares	Dec. 26, 2017 $ / shares	Feb. 29, 2020	Apr. 30, 2019 USD ($) $ / shares shares	Feb. 28, 2019 USD ($) shares	May 31, 2016 USD ($) $ / shares shares	Mar. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) shares	Jul. 15, 2019 shares	Dec. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2019 $ / shares	Feb. 28, 2018 USD ($)	Nov. 30, 2017 USD ($)
Class of Stock [Line Items]
Common stock, shares authorized									50,000,000			50,000,000
Common stock, shares issued									16,080,616			16,081,000
Common stock, shares outstanding									16,080,616			16,081,000
Common stock, par value | $ / shares									$ 0.001			$ 0.001
Reverse stock split, description	one-for-ten				1-for-10
Reverse stock split, conversion ratio	0.10
Reduction in the number of shares of common stock		16,100,000							160,800,000
Common stock sales agreement, aggregate offering amount | $									$ 161,000			$ 161,000
Offering Warrants
Class of Stock [Line Items]
Warrants exercise price | $ / shares									$ 12.50
Settlement Warrants
Class of Stock [Line Items]
Warrants to purchase of common stock shares			200,000
Warrants exercise price | $ / shares			$ 30.00	$ 3.00									$ 30.00
Warrants exercisable period			1 year	1 year
Warrant expiration date									Jul. 15, 2019
Warrants exercised during period											0
Underwritten Public Offering
Class of Stock [Line Items]
Common stock, shares issued						2,173,913
Gross proceeds from common stock and warrant issed | $						$ 25,000,000
Percentage of beneficial ownership of voting securities						5.00%
Net proceeds from public offering | $						$ 22,800,000
Underwritten Public Offering | Offering Warrants
Class of Stock [Line Items]
Warrants to purchase of common stock shares						2,500,000
Warrants exercise price | $ / shares						$ 12.50
Warrants exercisable period						2 years
Warrant expiration period						2021-04
Class of Warrant or Right, Outstanding									2,500,000
Over Allotment Option | Offering Warrants
Class of Stock [Line Items]
Warrants to purchase of common stock shares						326,086
Other Investors | Underwritten Public Offering
Class of Stock [Line Items]
Common stock, shares issued						434,782
Other Investors | Underwritten Public Offering | Offering Warrants
Class of Stock [Line Items]
Warrants to purchase of common stock shares						434,782
S V B Leerink
Class of Stock [Line Items]
Stock issued during period, shares										470,777
Net proceeds from issuance of common stock | $										$ 10,300,000
Common stock value available for issuance in connection with future stock sales | $									$ 32,000,000
Common Stock
Class of Stock [Line Items]
Reduction in the number of shares of common stock		50,000,000							500,000,000
Common Stock | S V B Leerink
Class of Stock [Line Items]
Stock issued during period, shares							1,251,555
Net proceeds from issuance of common stock | $							$ 7,500,000
PIPE Warrants | Private Placement
Class of Stock [Line Items]
Common stock, shares issued								1,764,242
Shares issued, price per share | $ / shares								$ 9.65
Warrants exercise price | $ / shares								$ 10.00
Warrants exercisable period								5 years
Warrant expiration period								2021-05
Gross proceeds from issuance of private placement | $								$ 17,000,000
Exchange of unit to share								1
Warrants exercisable shares of common stock exercised									80,309
Cash proceeds | $									$ 800,000
Warrants exercisable shares of common stock outstanding									1,683,933
Board of Directors
Class of Stock [Line Items]
Reverse stock split, description		split ranging from 1-for-5 to 1-for-15.
Director and Executive Officer | PIPE Warrants | Private Placement
Class of Stock [Line Items]
Common stock, shares issued								54,402
Net offering proceeds to the company | $								$ 15,400,000
Minimum
Class of Stock [Line Items]
Bid price per share | $ / shares	$ 1.00
Minimum | Underwritten Public Offering
Class of Stock [Line Items]
Shares issued, price per share | $ / shares						$ 11.40
Minimum | Underwritten Public Offering | Offering Warrants
Class of Stock [Line Items]
Shares issued, price per share | $ / shares						$ 0.10
Minimum | Board of Directors
Class of Stock [Line Items]
Reverse stock split, conversion ratio		0.066
Maximum
Class of Stock [Line Items]
Offering, issuance and sale of stocks and securities, shelf registration | $															$ 200,000,000
Maximum | S V B Leerink
Class of Stock [Line Items]
Common stock sales agreement, aggregate offering amount | $														$ 50,000,000
Common stock sales agreement commission, percentage														3.00%
Maximum | Board of Directors
Class of Stock [Line Items]
Reverse stock split, conversion ratio		0.2