Note 14 - Accumulated Other Comprehensive Income - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Taxes at effective rate			$ (45)	$ (1,013)	$ (73)
Net Income			58	1,350	94
Net gain on sale of securities			103	2,363	167
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Actuarial Losses [Member]
Other expense	[1]	$ (192)	(307)	(575)	(920)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Prior Service Credits [Member]
Other expense	[1]	11	11	33	34
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Total before tax		(181)	(296)	(542)	(886)
Taxes at effective rate		78	129	233	387
Net Income		(103)	(167)	(309)	(499)
Total before tax		17,289	17,669	83,617	56,303
Taxes at effective rate		6,655	6,661	32,987	21,728
Net Income		10,634	11,008	50,630	34,575
Net gain on sale of securities			$ 103	$ 2,363	$ 167

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (See Note 10 of the Notes to Consolidated Financial Statements "Pension and Other Postretirement Benefit Plans".)