Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Assumptions Used to Determine Benefit Obligations and Periodic Pension Expense for the Directors’ Plan	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Assumptions Used to Determine Benefit Obligations and Periodic Pension Expense for the Directors’ Plan [Line Items]
Weighted average discount rate for periodic pension benefit expense	4.60%	3.75%	4.25%
Rate of increase in future compensation levels
Directors' Plan [Member]
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Assumptions Used to Determine Benefit Obligations and Periodic Pension Expense for the Directors’ Plan [Line Items]
Weighted average discount rate for the benefit obligation	3.76%	4.60%	3.75%
Weighted average discount rate for periodic pension benefit expense	4.60%	3.75%	4.25%
Rate of increase in future compensation levels