Note 8 - Allocation of Plan Assets (Details)	Dec. 31, 2015	Dec. 31, 2014
Insurance General Account [Member]
Asset category:
Plan assets, percent	26.00%	28.00%
Cash and Cash Equivalents [Member]
Asset category:
Plan assets, percent	2.00%	3.00%
Equity Securities [Member]
Asset category:
Plan assets, percent	54.00%	64.00%
Fixed Income Securities [Member]
Asset category:
Plan assets, percent	14.00%	5.00%
Real Estate [Member]
Asset category:
Plan assets, percent	4.00%	0.00%
Plan assets, percent	100.00%	100.00%