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Exercise price per share or per unit of warrants or rights outstanding.

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The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

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Note 10 - Secured Promissory Note Payable to Oxford Finance (Details Textual) - USD ($)			12 Months Ended
	Nov. 04, 2019	Dec. 22, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 13, 2018
Debt Conversion, Converted Instrument, Amount					$ 35,577,000
Amortization of Debt Issuance Costs	$ 98,000
Legal Fees	$ 2,000
Warrants in Connection with Loan Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		7,563				10,914
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 33.11				$ 22.99
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 134,000				$ 70,000
Loan Agreement [Member] \| Oxford Finance [Member]
Long-term Debt, Gross		$ 5,000,000
Debt Instrument, Term (Year)		4 years
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid		$ 325,000
Debt Conversion, Converted Instrument, Amount		$ 250,000
Debt Instrument, Interest Rate, Effective Percentage						10.50%
Interest Expense, Debt, Total				311,000	526,000
Interest Paid, Including Capitalized Interest, Operating and Investing Activities, Total				$ 223,000	$ 356,000
Loan Agreement [Member] \| Oxford Finance [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		6.17%