At-the-Market Offering - Additional Information (Detail) - USD ($)				1 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 01, 2020	Mar. 27, 2020	Aug. 11, 2020	Jun. 30, 2020	Dec. 31, 2019
Changes In Equity And Comprehensive Income Line Items [Line Items]
Common stock par value	$ 0.0001				$ 0.0001	$ 0.0001
Net proceeds from offering					$ 22,780,729
Equity Distribution Agreement [Member] | At-The-Market Offering [Member] | JMP Securities LLC [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Common stock par value			$ 0.0001
Aggregate offering price		$ 50,000,000	$ 18,900,000
Shares of common stock sold	2,965,144
Net proceeds from offering	$ 22,800,000
Common stock available to be sold	26,300,000				26,300,000
Deferred offering costs	200,000				$ 200,000
Issuance costs	$ 300,000
Equity Distribution Agreement [Member] | At-The-Market Offering [Member] | JMP Securities LLC [Member] | Subsequent Event [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Shares of common stock sold				234,856
Net proceeds from offering				$ 2,500,000
Common stock available to be sold				$ 23,700,000
Equity Distribution Agreement [Member] | At-The-Market Offering [Member] | JMP Securities LLC [Member] | Maximum [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Aggregate offering price			$ 50,000,000