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Number of common units of ownership outstanding of a limited liability company (LLC).

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Common Stock - Additional Information (Detail) - USD ($)					12 Months Ended
	Jul. 16, 2020	Jun. 01, 2020	Mar. 27, 2020	Mar. 12, 2019	Dec. 31, 2020	Dec. 31, 2019
Changes In Equity And Comprehensive Income Line Items [Line Items]
Issuance of common stock, net (in shares)	3,369,564
Proceeds from issuance of common stock in public offering, net					$ 48,156,072
Common stock, par or stated value per share					$ 0.0001	$ 0.0001
Shares of common stock sold	3,369,564
Pre-Funded Warrants [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Number of securities called by warrants or rights					0
Number of securities called by warrants or rights					0
Public Offering [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Gross proceeds from offering including exercise of underwriter's option	$ 132,200,000
Public Offering [Member] \| Pre-Funded Warrants [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Exercise price of warrants or rights	$ 0.0001
Purchase price of warrants issued	$ 22.9999
Ownership percentage on exercise of warrants without notice, minimum	4.99%
Ownership percentage on exercise of warrants with notice, maximum	19.99%
Notice period to increase ownership percentage on exercise of warrants	61 days
Per share exercise price	$ 0.0001
Public Offering [Member] \| Common Stock [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Public offering price, per share	$ 23.00
Public Offering [Member] \| Common Stock [Member] \| Pre-Funded Warrants [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Number of securities called by warrants or rights	1,630,436
Number of securities called by warrants or rights	1,630,436
Over-Allotment Option [Member] \| Common Stock [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Issuance of common stock, net (in shares)	750,000
Proceeds from issuance of common stock in public offering, net	$ 124,000,000
Shares of common stock sold	750,000
At-The-Market Offering [Member] \| Equity Distribution Agreement [Member] \| JMP Securities LLC [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Issuance of common stock, net (in shares)					5,594,455
Proceeds from issuance of common stock in public offering, net					$ 48,200,000
Common stock, par or stated value per share			$ 0.0001
Aggregate offering price		$ 50,000,000	$ 18,900,000
Shares of common stock sold					5,594,455
Issuance costs					$ 300,000
At-The-Market Offering [Member] \| Equity Distribution Agreement [Member] \| JMP Securities LLC [Member] \| Maximum [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Aggregate offering price			$ 50,000,000
Registered Direct Offering [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Proceeds from issuance of common stock in public offering, net				$ 12,700,000
Issuance of transaction date				Mar. 12, 2019
Common units outstanding				4,361,370
Warrant expiration period				5 years
Deemed Dividend						$ 452,925
Registered Direct Offering [Member] \| Maximum [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Exercise price of warrants or rights				$ 4.1798		$ 4.1798
Per share exercise price				4.1798		4.1798
Registered Direct Offering [Member] \| Minimum [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Per share exercise price				$ 2.7568		$ 2.7568
Registered Direct Offering [Member] \| Common Units [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Number of securities called by warrants or rights				0.70
Number of securities called by warrants or rights				0.70
Public offering price per share				$ 3.21
Per share exercise price				$ 3.21
Registered Direct Offering [Member] \| Prefunded Units [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Number of securities called by warrants or rights				0.70
Exercise price of warrants or rights				$ 0.01
Number of securities called by warrants or rights				0.70
Public offering price per share				$ 3.20
Per share exercise price				3.21
Per share exercise price				$ 0.01