Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Amounts Recognized in Accumulated Other Comprehensive Income, on a Pre-Tax Basis (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Amounts Recognized in Accumulated Other Comprehensive Income, on a Pre-Tax Basis [Line Items]
Net Actuarial loss (gain)	$ 11,580	$ 5,608	$ 12,633
Prior Service cost (credit)	(492)	(537)	(584)
Total	11,088	5,071	12,049
Retirement Plan [Member]
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Amounts Recognized in Accumulated Other Comprehensive Income, on a Pre-Tax Basis [Line Items]
Net Actuarial loss (gain)	9,938	5,899	11,843
Total	9,938	5,899	11,843
Other Postretirement Benefit Plans [Member]
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Amounts Recognized in Accumulated Other Comprehensive Income, on a Pre-Tax Basis [Line Items]
Net Actuarial loss (gain)	2,130	205	1,199
Prior Service cost (credit)	(623)	(708)	(794)
Total	1,507	(503)	405
Directors' Plan [Member]
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - Amounts Recognized in Accumulated Other Comprehensive Income, on a Pre-Tax Basis [Line Items]
Net Actuarial loss (gain)	(488)	(496)	(409)
Prior Service cost (credit)	131	171	210
Total	$ (357)	$ (325)	$ (199)