Note 15 - Benefit Plans (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.25%
Defined Contribution Plan, Cost Recognized	$ 1.2	$ 1.2	$ 0.9
Stock Issued During Period, Shares, Employee Stock Purchase Plans	1,362	2,058
Stock Purchase Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance	250,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	245,430
Maximum [Member]
Interest Expense, Deferred Compensation Plan	$ 0.1	$ 0.1	$ 0.1
Other Liabilities [Member]
Deferred Compensation Liability, Current and Noncurrent	$ 3.4	$ 3.9