Note 7 - Fair Value Measurements - Fair Value of Liabilities on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Warrant derivative liabilities		$ (1,871)
Total warrant derivative liabilities		(1,871)
Fair Value, Inputs, Level 1 [Member]
Warrant derivative liabilities
Total warrant derivative liabilities
Fair Value, Inputs, Level 2 [Member]
Warrant derivative liabilities
Total warrant derivative liabilities
Fair Value, Inputs, Level 3 [Member]
Warrant derivative liabilities		(1,871)
Total warrant derivative liabilities		$ (1,871)