Note 2 - Summary of Significant Accounting Policies - Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income (loss)		$ 13,925	$ (4,720)	$ (7,843)	$ (9,012)
Weighted-average common shares outstanding (in shares)	[1]	13,885	9,168	11,578	9,168
Shares issuable for warrants (in shares)		414
Shares used in calculation - diluted (in shares)		14,299	9,168	11,578	9,168
Basic (in dollars per share)		$ 1	$ (0.51)	$ (0.68)	$ (0.98)
Diluted (in dollars per share)		$ 0.97	$ (0.51)	$ (0.68)	$ (0.98)

[1] The financial statements have been retroactively restated to reflect the 1-for-6 reverse-stock split that occurred on April 25, 2017.