Note 9 - Income Taxes - Allocation of Income Tax Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current	$ 2,942,000	$ 2,943,000	$ 3,934,000
Deferred expense (benefit)	(382,000)	1,790,000	18,000
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		1,560,000
Total income tax expense	$ 2,560,000	$ 6,293,000	$ 3,952,000