Fair Value - Additional Information (Detail)		12 Months Ended
	Apr. 28, 2017 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 11, 2019 $ / shares	Dec. 31, 2017 shares
Fair Value Measurements Disclosure [Line Items]
Transfers of assets		$ 0	$ 0
Transfers of liabilities		0	0
Change in fair value of contingent consideration		9,553,000	1,011,000
Offering price (in dollars per share) | $ / shares	$ 1.00
Change in fair value of warrant liabilities		(2,248,000)	14,320,000
Series A Warrant
Fair Value Measurements Disclosure [Line Items]
Warrants, exercise price (in dollars per share) | $ / shares	$ 13.00
Series A Warrant | Black-Scholes Merton Model
Fair Value Measurements Disclosure [Line Items]
Estimated fair value of warrants	$ 2,500,000
Share price (in dollars per share) | $ / shares	$ 8.45
Series A Warrant | Black-Scholes Merton Model | Measurement Input, Expected Term
Fair Value Measurements Disclosure [Line Items]
Fair value input, term	1 year
Series A Warrant | Black-Scholes Merton Model | Measurement Input, Risk Free Interest Rate
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate	0.0107
Series A Warrant | Black-Scholes Merton Model | Measurement Input, Expected Dividend Payment
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate	0
Series A Warrant | Black-Scholes Merton Model | Measurement Input, Price Volatility
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate	0.7314
Series B Warrant
Fair Value Measurements Disclosure [Line Items]
Warrants, exercise price (in dollars per share) | $ / shares	$ 13.00			$ 1.39
Estimated fair value of warrants		$ 2,400,000	$ 4,600,000
Share price (in dollars per share) | $ / shares		$ 1.47	$ 29.38
Series B Warrant | Measurement Input, Expected Term
Fair Value Measurements Disclosure [Line Items]
Fair value input, term		2 years 3 months 25 days	3 years 3 months 25 days
Series B Warrant | Measurement Input, Risk Free Interest Rate
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate		0.0159	0.0247
Series B Warrant | Measurement Input, Expected Dividend Payment
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate		0	0
Series B Warrant | Measurement Input, Price Volatility
Fair Value Measurements Disclosure [Line Items]
Fair value input, risk free rate		1.0980	0.8760
Common Stock | Series A
Fair Value Measurements Disclosure [Line Items]
Gross proceeds from public offering	$ 24,900,000
Common Stock | Series A Warrant
Fair Value Measurements Disclosure [Line Items]
Number of common stock or warrants in each unit | shares	0.077
Common Stock | Series B Warrant
Fair Value Measurements Disclosure [Line Items]
Gross proceeds from public offering	$ 24,900,000
Number of common stock or warrants in each unit | shares	0.058
Warrants Not Settleable in Cash
Fair Value Measurements Disclosure [Line Items]
Number of warrants outstanding (in shares) | shares					1,012,513
Warrants Not Settleable in Cash | Series B Warrant
Fair Value Measurements Disclosure [Line Items]
Number of warrants outstanding (in shares) | shares		1,963,451