Note 12 - Subsequent Events (Details Textual) - USD ($) $ in Thousands	May 29, 2019	May 14, 2019	Mar. 31, 2019		Dec. 31, 2018		Oct. 12, 2016
Debt Instrument, Face Amount			$ 87,493		$ 80,691
Convertible Second Lien Notes [Member]
Debt Instrument, Face Amount			$ 55,493	[1]	$ 53,691	[1]	$ 40,000
Debt Instrument, Interest Rate, Stated Percentage							13.50%
Convertible Second Lien Notes [Member] | Forecast [Member]
Debt Conversion, Original Debt, Amount	$ 56,700
New Convertible Second Lien Notes, New 2L Notes [Member] | Subsequent Event [Member]
Debt Instrument, Face Amount		$ 12,000
Debt Instrument, Interest Rate, Stated Percentage		13.50%

[1] The debt discount is being amortized using the effective interest rate method based upon a maturity date of August 30, 2019. The principal includes $15.5 million and $13.7 million of paid in-kind interest as of March 31, 2019 and December 31, 2018, respectively. The carrying value includes $2.5 million and $3.9 million of unamortized debt discount as of March 31, 2019 and December 31, 2018, respectively.