Note 11 - Federal Income Taxes -Consolidated Income Tax Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current expense	$ 15,786,000	$ 7,399,000	$ 3,359,000
Deferred expense	(699,000)	4,592,000	4,506,000
Change in valuation allowance	(113,000)	(180,000)	0
Tax expense	$ 14,974,000	$ 11,811,000	$ 7,865,000