Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended	12 Months Ended
	Mar. 06, 2020	Aug. 09, 2019	Mar. 28, 2019	Aug. 06, 2018	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Jan. 22, 2018
Class of Stock [Line Items]
Number of shares issued (in shares)				12,062,000
Number of additional shares from warrants (in shares)			2,500,000	4,221,700	1,255,129	1,255,129
Gross proceeds				$ 19,700
Exercise price per share (in dollars per share)			$ 7.00	$ 2.52
Stock issuance costs				$ 500		$ 0	$ 500
Proceeds from the exercise of warrants			$ 10,600		$ 6,900	$ 17,542	$ 0
Preferred stock, shares authorized (in shares)					2,000,000	2,000,000	2,000,000
Preferred stock, par value (in dollars per share)					$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares outstanding (in shares)					0	0	0
Number of rights issued per common stock (in shares)								1
Gross proceeds received from issuance of Series E preferred stock						$ 10,000	$ 0
Dividends accrued					$ 400	$ 400
Percent threshold for acquiring common stock in order to remain Grandfathered Stockholders						0.50%
Series D Preferred Stock
Class of Stock [Line Items]
Exercise price per share (in dollars per share)								$ 10.00
Preferred stock, shares authorized (in shares)					150,000	150,000
Preferred stock, par value (in dollars per share)								$ 0.001
Number of preferred shares issued from exercise of right (in shares)								0.001
Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					39,500	39,500
Preferred stock, par value (in dollars per share)		$ 0.001
Preferred stock, shares issued (in shares)		10,000
Gross proceeds received from issuance of Series E preferred stock		$ 10,000
Dividend rate		9.00%
Redemption price		110.00%
Liquidation preference per share (in dollars per share)		$ 1,000
Subsequent Event | Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	25,000
Purchase price (in dollars per share)	$ 1,000
Gross proceeds received from issuance of Series E preferred stock	$ 25,000