Note 10 - Pension and Other Postretirement Benefit Plans (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Directors' Plan [Member]
Note 10 - Pension and Other Postretirement Benefit Plans (Details) [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		$ 300,000
Defined Benefit Plan, Contributions by Employer	$ 76,000
Other Postretirement Benefit Plan [Member]
Note 10 - Pension and Other Postretirement Benefit Plans (Details) [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		$ 200,000
Defined Benefit Plan, Contributions by Employer	$ 37,000