Note 11 - Recent Accounting and Reporting Developments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2018
Income Tax Expense (Benefit)	$ (1,375)	$ (131)	$ (1,596)	$ (663)
Accounting Standards Update 2016-09 [Member]
Income Tax Expense (Benefit)			$ 800
Accounting Standards Update 2017-07 [Member] | Scenario, Forecast [Member] | Year Ended December 31, 2016 [Member] | Cost of Sales [Member]
Prior Period Reclassification Adjustment					$ (400)
Accounting Standards Update 2017-07 [Member] | Scenario, Forecast [Member] | Year Ended December 31, 2016 [Member] | Other Expense [Member]
Prior Period Reclassification Adjustment					$ 400