Summary of Significant Accounting Policies - Financial Instruments (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended			3 Months Ended	12 Months Ended
	Dec. 16, 2021	Nov. 25, 2019	Dec. 31, 2021	Jun. 30, 2021	Jan. 31, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Amount paid for clearing fees					$ 231
Offering costs paid on the issuance of common stock and warrants							$ 969	$ 510
Percent proceeds to be paid to Lender					10.00%
Payments on the Iliad Note							$ 0	1,306
Warrants exercised (in shares)							237,892
Proceeds from the exercise of warrants							$ 801	$ 918
December 2021 Private Placement
Class of Stock [Line Items]
Sale of common stock (in shares)			1,193,185
Sale of common stock (USD per share)			$ 3.52			$ 3.52	$ 3.52
Securities called by warrants (in shares)			1,363,641			1,363,641	1,363,641
Exercise price of warrants (in dollars per share)			$ 3.30			$ 3.30	$ 3.30
Number of warrants issued (in shares)							1,363,641
Amount paid for placement agent commissions			$ 360
Amount paid related to expenses for registered direct offering and concurrent private placement			42
Amount paid for clearing fees			97
Offering costs paid on the issuance of common stock and warrants			499
Net proceeds from sale of common stock and warrants			$ 4,000
Warrants exercised (in shares)							0
Estimated proceeds from issuance of warrants							$ 4,500
December 2021 Private Placement | Pre-Funded Warrants
Class of Stock [Line Items]
Securities called by warrants (in shares)			85,228			85,228	85,228
Exercise price of warrants (in dollars per share)			$ 0.0001			$ 0.0001	$ 0.0001
Number of warrants issued (in shares)	85,228						85,228
December 2021 Private Placement | Common Warrants
Class of Stock [Line Items]
Securities called by warrants (in shares)			1,278,413			1,278,413	1,278,413
Exercise price of warrants (in dollars per share)			$ 3.5200			$ 3.5200	$ 3.5200
Number of warrants issued (in shares)							1,278,413
Investor Warrants
Class of Stock [Line Items]
Sale of common stock (in shares)				990,100
Sale of common stock (USD per share)				$ 5.05
Number of warrants issued (in shares)							187,734	425,626
Amount paid for placement agent commissions				$ 400
Amount paid related to expenses for registered direct offering and concurrent private placement				51
Amount paid for clearing fees				19
Offering costs paid on the issuance of common stock and warrants							$ 470
Net proceeds from sale of common stock and warrants				$ 4,500
January 2020 Equity Offering
Class of Stock [Line Items]
Exercise price of warrants (in dollars per share)			$ 3.67			$ 3.67	$ 3.67	$ 3.51
Number of warrants issued (in shares)						229,414	229,414	467,306
Amount paid for placement agent commissions					$ 193
Amount paid related to expenses for registered direct offering and concurrent private placement					50
Amount paid for clearing fees					231
Offering costs paid on the issuance of common stock and warrants							$ 510	$ 510
Net proceeds from sale of common stock and warrants					2,300
Gross proceeds from equity issuance					275
Warrants exercised (in shares)								269,240
Estimated proceeds from issuance of warrants							841
Proceeds from the exercise of warrants							$ 801	$ 918
January 2020 Equity Offering | Iliad Note
Class of Stock [Line Items]
Percent proceeds to be paid to Lender		10.00%
Payments on the Iliad Note					$ 226
January 2020 Institutional Investor
Class of Stock [Line Items]
Sale of common stock (in shares)					688,360
Sale of common stock (USD per share)					$ 3.37
Securities called by warrants (in shares)					688,360
Exercise price of warrants (in dollars per share)					$ 3.37
Purchase price (in dollars per share)					$ 0.625
January 2020 Equity Offering, Private Placement
Class of Stock [Line Items]
Securities called by warrants (in shares)					48,185
Exercise price of warrants (in dollars per share)					$ 4.9940
Number of warrants issued (in shares)							41,680	41,680
Amount paid for placement agent commissions					$ 193
Amount paid related to expenses for registered direct offering and concurrent private placement					$ 50