Annual report pursuant to Section 13 and 15(d)

Debt Agreements - Additional information (Details)

Debt Agreements - Additional information (Details) - USD ($)			1 Months Ended					3 Months Ended	12 Months Ended
	Apr. 20, 2020	Jul. 27, 2017	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2018	Feb. 28, 2018	Jul. 27, 2017	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Oct. 31, 2020	Sep. 30, 2018	Mar. 21, 2018
Class of Warrant or Right, Number of Securities Called by Warrants or Rights									1,112,313
Gain (Loss) on Extinguishment of Debt									$ (81,000)	$ 226,000
Loan proceeds									654,000	0
Current portion of long-term debt									327,000	0
Long-term debt, net of debt discount of $0 and $346									332,000	4,019,000
Horizon Technology Finance Corporation
Class of Warrant or Right, Exercise Price of Warrants or Rights												$ 45.00
Class of Warrant or Right, Number of Securities Called by Warrants or Rights												12,223
Class Of Warrant Or Right Terms		7 years
Venture Loan
Debt Instrument, Face Amount		$ 7,000,000					$ 7,000,000
Debt Instrument Final Payment On Each Loan Tranche percentage							5.00%
Early Repayment of Subordinated Debt						$ 3,000,000
Long-term Debt						$ 7,000,000
Venture Loan \| Horizon Technology Finance Corporation
Debt Instrument, Term		46 months
Debt Instrument, Description of Variable Rate Basis							one-month LIBOR (floor of 1.10%) plus 8.40%
Molteni Loan
Class Of Warrant Or Right Terms					7 years
Long-term Debt													$ 4,000,000
Conversion Price, (in dollars per share)			$ 6.75
Debt Conversion, Converted Instrument, Shares Issued			114,093
Gain (Loss) on Extinguishment of Debt										$ 300,000
Increase in Repayment of Long-term Debt			$ 300,000
Horizon Loan
Class of Warrant or Right, Exercise Price of Warrants or Rights													$ 216.00
Class of Warrant or Right, Number of Securities Called by Warrants or Rights													223
Long-term Debt													$ 2,400,000
Conversion Price, (in dollars per share)													$ 216.00
Stockholders' Equity Note, Changes in Capital Structure, Subsequent Changes to Number of Common Shares, Amount					$ 10,000,000
Debt Instrument, Periodic Payment					$ 1,600,000
Horizon and Molteni Loans
Long-term Debt											$ 1,600,000
Gain (Loss) on Extinguishment of Debt									(100,000)
Molteni Purchase Agreement
Conversion Price, (in dollars per share)				$ 45.00
Debt Conversion, Converted Instrument, Shares Issued				14,943
Gain (Loss) on Extinguishment of Debt				$ (100,000)
PPP loans
Debt Instrument, Term	6 months
Loan proceeds	$ 654,000
Loan annual interest rate	1.00%
Current portion of long-term debt									300,000
Long-term debt, net of debt discount of $0 and $346									$ 300,000
Minimum \| Venture Loan \| Horizon Technology Finance Corporation
Debt Instrument Additional Face Amount		$ 10,000,000					$ 10,000,000
Maximum \| PPP loans
Debt Instrument, Term								16 months
New Horizon Warrants
Class of Warrant or Right, Exercise Price of Warrants or Rights													$ 216.00
Class of Warrant or Right, Number of Securities Called by Warrants or Rights													3,000