Note 8 - Actual and Target Pension Plan Asset Allocation (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Equity Securities [Member]
Percentage of plan assets	64.00%	63.00%
Target allocation	65.00%
Fixed Income Investments [Member]
Percentage of plan assets	15.00%	15.00%
Target allocation	15.00%
Other than Securities Investment [Member]
Percentage of plan assets	21.00%	22.00%
Target allocation	20.00%
Percentage of plan assets	100.00%	100.00%
Target allocation	100.00%