Note 1 - Business and Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		33 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($) $ / shares	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($) $ / shares	Sep. 30, 2019 USD ($)
Number of Businesses	1		1
Income Tax Expense (Benefit)	$ 3,394	$ (3,412)	$ 9,302	$ 4,326
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income		1,900		1,900
Income Tax Expense (Benefit)		$ (1,900)		$ (1,900)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share | $ / shares		$ 0.02		$ 0.02
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share | $ / shares		$ 0.02		$ 0.02
Increase to Net Cash From Operations and Net Cash Used in Financing [Member] | Nine Months Ended September 30, 2016 [Member] | Accounting Standards Update 2016-09 [Member]
Prior Period Reclassification Adjustment					$ 1,900