Note 9 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance			$ (2,666,000)	$ (1,582,000)
Unrealized holding loss on available for sale securities, net of tax			4,484,000	(624,000)
Reclassification adjustment, net of tax			(99,000)	(3,000)
Balance	$ 1,719,000	$ (2,209,000)	1,719,000	(2,209,000)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance			(5,270,000)	(4,090,000)
Unrealized holding loss on available for sale securities, net of tax			0	0
Reclassification adjustment, net of tax			0	0
Balance	(5,270,000)	(4,090,000)	(5,270,000)	(4,090,000)
Balance			(7,936,000)	(5,672,000)
Unrealized holding loss on available for sale securities, net of tax	454,000	2,589,000	4,484,000	(624,000)
Reclassification adjustment, net of tax	(66,000)	(1,000)	(99,000)	(3,000)
Balance	$ (3,551,000)	$ (6,299,000)	$ (3,551,000)	$ (6,299,000)