Note 3 - Accumulated Other Comprehensive Income (Details) - Changes in Accumulated Other Comprehensive Income by Component (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 4,875	$ (3,212)
Other comprehensive income (loss) before reclassifications	648	3,635
Amounts reclassified from accumulated other comprehensive income	(57)	74
Net current-period other comprehensive income (loss)	591	3,709
Ending balance	5,466	497
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	5,174	(3,623)
Other comprehensive income (loss) before reclassifications	1,899	3,635
Amounts reclassified from accumulated other comprehensive income	(72)	51
Net current-period other comprehensive income (loss)	1,827	3,686
Ending balance	7,001	63
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(299)	411
Other comprehensive income (loss) before reclassifications	(1,251)	0
Amounts reclassified from accumulated other comprehensive income	15	23
Net current-period other comprehensive income (loss)	(1,236)	23
Ending balance	$ (1,535)	$ 434