Equity Transactions - Rights Offering - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended
	Mar. 05, 2020	Feb. 11, 2020	Mar. 31, 2021	Mar. 31, 2020	Feb. 28, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, par value			$ 0.001			$ 0.001
Aggregate issue costs			$ 37	$ 352
Common Stock [Member]
Class Of Stock [Line Items]
Issuance of stock, shares	1,046,249		257,185	1,046,249
Aggregate issue costs			$ 130	$ 462
Series C Preferred Stock [Member]
Class Of Stock [Line Items]
Issuance of Common Stock, conversion of Preferred Stock to Common Stock	$ 20,600	$ 30,000
Right to purchase common stock shares		0.152
Common stock, par value		$ 9.00
Issuance of stock, shares	2,287
Aggregate issue costs	$ 100			$ 41
Number of shares issuable upon conversion			1,000		73,000
Preferred stock, liquidation per share			$ 0.001
Voting rights			no
Share price	$ 9.22
Intrinsic value of beneficial conversion feature			$ 500
Common Stock and Series C Preferred Stock [Member]
Class Of Stock [Line Items]
Issuance of Common Stock, conversion of Preferred Stock to Common Stock	$ 30,000
Amount of agreed to purchase offered shares and not subscribed shares value under rights offering			$ 30,000
Aggregate issue costs	$ 500
Series A Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Share price	$ 8.98