Note 9 - Income Taxes (Details) - Analysis of Effective and Statutory Federal Income Tax Rates	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Note 9 - Income Taxes (Details) - Analysis of Effective and Statutory Federal Income Tax Rates [Line Items]
Federal statutory rate	35.00%	35.00%	35.00%
Changes from statutory rates resulting from:
Company-owned life insurance	(1.80%)	(3.50%)	(15.20%)
Uncertain tax position	(0.50%)	(0.90%)	14.30%
Other, net	(0.60%)	(0.30%)	1.40%
Effective tax rate on pretax income	24.80%	19.30%	(30.90%)
Tax credits	0.00%	(1.80%)	(13.00%)
Interest Income [Member]
Changes from statutory rates resulting from:
Tax-Exempt	(6.30%)	(7.60%)	(51.50%)
Interest To Carry Tax Exempt Obligations [Member]
Changes from statutory rates resulting from:
Nondeductible	0.30%	0.40%	3.60%
Legal Expense [Member]
Changes from statutory rates resulting from:
Nondeductible	0.00%	0.50%	0.00%
Other Income [Member]
Changes from statutory rates resulting from:
Tax-Exempt	(1.30%)	(2.50%)	(5.50%)