Basis of Presentation and Summary of Significant Accounting Policies - Financial Instruments (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		12 Months Ended
	Nov. 25, 2019	Jan. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Class of Stock [Line Items]
Warrants issued (in shares)			310,860	736,545
Exercise price of common stock (in dollars per share)			$ 3.59
Amount paid for clearing fees		$ 231
Offering costs paid on the issuance of common stock and warrants			$ 0	$ (474)	$ (510)
Proceeds from sale of common stock		$ 2,300
Percentage of gross proceeds used to make payments on note		10.00%
Gross proceeds		$ 275
Payments on the Iliad Note			0	226
Proceeds from issuance of warrants			$ 1,100
Warrants exercised (in shares)			(156,446)
Proceeds from the exercise of warrants			$ 527	$ 0
Note Purchase Agreement
Class of Stock [Line Items]
Percentage of gross proceeds used to make payments on note	10.00%
Payments on the Iliad Note		$ 226
Investor Warrants
Class of Stock [Line Items]
Sale of common stock (in shares)		688,360
Sale of common stock (in dollars per share)		$ 3.37
Warrants issued (in shares)		688,360	269,180	688,360
Exercise price of common stock (in dollars per share)		$ 3.37	$ 3.3700	$ 3.3700
Purchase price (in usd per share)		$ 0.625
Placement Agent Warrants
Class of Stock [Line Items]
Warrants issued (in shares)		48,185	41,680	48,185
Exercise price of common stock (in dollars per share)		$ 4.99	$ 4.9940
Amount paid for placement agent commissions		$ 193
Amount paid related to expenses for registered direct offering and concurrent private placement		$ 50