Note 2 - Accumulated Other Comprehensive Income (Details) - Changes in Accumulated Other Comprehensive Income by Component - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 4,875	$ (3,212)
Other comprehensive (loss) income before reclassifications	(2,048)	7,933
Amounts reclassified from accumulated other comprehensive income	(45)	154
Net current-period other comprehensive (loss) income	(2,093)	8,087
Ending balance	2,782	4,875
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	5,174	(3,623)
Other comprehensive (loss) income before reclassifications	(1,850)	8,734
Amounts reclassified from accumulated other comprehensive income	(105)	63
Net current-period other comprehensive (loss) income	(1,955)	8,797
Ending balance	3,219	5,174
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(299)	411
Other comprehensive (loss) income before reclassifications	(198)	(801)
Amounts reclassified from accumulated other comprehensive income	60	91
Net current-period other comprehensive (loss) income	(138)	(710)
Ending balance	$ (437)	$ (299)