Warrant Liabilities - Additional information (Detail) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020 $ / shares shares	Jun. 30, 2020 USD ($) $ / shares shares
Class of Warrant or Right [Line Items]
Non-cash expense on warrant liability | $		$ 16,240
Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant expiration period after specified event	5 years	5 years
Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant expiration period after specified event	75 days	75 days
Exercise of Future Warrants Value | $		$ 34,000
Underwritten Follow On Offerings [Member] | Series A Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securitites called by warrants and rights | shares	7,802,241	7,802,241
Excercise price of warrants or rights | $ / shares	$ 13.20	$ 13.20
Underwritten Follow On Offerings [Member] | Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Number of securitites called by warrants and rights | shares	2,574,727	2,574,727
Excercise price of warrants or rights | $ / shares	$ 13.20	$ 13.20