Note 16 - Employee Benefit Plans - (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Employee Compensation and Benefits	$ 542,000	$ 467,000	$ 351,000
Deferred Compensation Arrangement with Individual, Recorded Liability	2,100,000	2,000,000
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 209,000		$ 336,000
Deferred Compensation Arrangement with Individual, Reversal of Accrued Liabilities		$ 339,000