Note 7- Embedded Derivatives and Derivative Warrant Liabilities - Schedule of Shares Issued Upon Exercise of Warrants (Details) - $ / shares	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Shares Underlying Warrants (in shares)	50,812	396,242
Shares Issues Upon Warrant Exercises (in shares)	345,430
Series D Warrants [Member]
Warrant, Issuance Date	Dec. 11, 2015
Warrants, Expiration date	Dec. 11, 2020
Warrant Exercise Price (in dollars per share)	$ 40
Shares Underlying Warrants (in shares)	47	25,125
Shares Issues Upon Warrant Exercises (in shares)	25,078
Series F Warrants [Member]
Warrant, Issuance Date	Apr. 01, 2016
Warrants, Expiration date	Apr. 01, 2021
Warrant Exercise Price (in dollars per share)	$ 40
Shares Underlying Warrants (in shares)	14,041	25,733
Shares Issues Upon Warrant Exercises (in shares)	11,692
Series I Warrants [Member]
Warrant, Issuance Date	Sep. 13, 2016
Warrants, Expiration date	Sep. 13, 2021
Warrant Exercise Price (in dollars per share)	$ 220
Shares Underlying Warrants (in shares)	35,368	35,368
Shares Issues Upon Warrant Exercises (in shares)
Series K Warrants [Member]
Warrant, Issuance Date	Feb. 17, 2017
Warrants, Expiration date	Feb. 17, 2022
Warrant Exercise Price (in dollars per share)	$ 3.80
Shares Underlying Warrants (in shares)	1,356	310,016
Shares Issues Upon Warrant Exercises (in shares)	308,660