Note 2 - Summary of Significant Accounting Policies - Cumulative Effect of Adjustments for New Accounting Pronouncements on Consolidated Balance Sheet (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	[1]
Other assets		$ 587	$ 800	$ 171
Total assets		24,149	47,463	46,834
Total accrued liabilities		4,457	6,996	6,766
Total current liabilities		6,248	10,990	10,760
Other noncurrent liabilities		997	1,033	634
Total liabilities		38,939	42,551	41,922
Total liabilities and stockholders' equity		$ 24,149	47,463	$ 46,834
Accounting Standards Update 2016-02 [Member]
Other assets	[2]		629
Total assets	[2]		629
Total accrued liabilities	[3]		230
Total current liabilities	[3]		230
Other noncurrent liabilities	[3]		399
Total liabilities	[3]		629
Total liabilities and stockholders' equity	[3]		$ 629

[1] The condensed consolidated balance sheet as of December 31, 2018 has been derived from the audited consolidated financial statements as of that date.

[2] Represents capitalization of operating lease right-of-use assets and reclassification of deferred rent.

[3] Represents recognition of operating lease liabilities.