Note 12 - Pension and Other Postretirement Benefit Plans (Details) - The Resulting Net Periodic Postretirement Expense Consisted of the Following Components for the Year (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - The Resulting Net Periodic Postretirement Expense Consisted of the Following Components for the Year [Line Items]
Amortization of prior service credit	$ (26)	$ (26)	$ (26)
Postretirement Plans [Member]
Note 12 - Pension and Other Postretirement Benefit Plans (Details) - The Resulting Net Periodic Postretirement Expense Consisted of the Following Components for the Year [Line Items]
Service cost	358	449	400
Interest cost	253	219	217
Amortization of unrecognized loss		50	40
Amortization of past service credit	(85)	(85)	(85)
Net postretirement benefit expense	526	633	572
Current year actuarial (gain) loss	1,925	(943)	211
Amortization of actuarial gain		(50)	(40)
Amortization of prior service credit	85	85	85
Total recognized in other comprehensive income	2,010	(908)	256
Total recognized in net postretirement expense and other comprehensive income	$ 2,536	$ (275)	$ 828