Note 14 - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Net gain on sale of securities		$ 2,363	$ 64	$ 2,363	$ 64
Tax expense (benefit)		(1,013)	(28)	(1,013)	(28)
Net income		1,350	36	1,350	36
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Actuarial Losses [Member]
Other expense	[1]	(192)	(306)	(384)	(613)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Prior Service Credits [Member]
Other expense	[1]	12	12	23	23
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Tax expense (benefit)		77	130	155	258
Net income		(103)	(164)	(206)	(332)
Total before tax		(180)	(294)	(361)	(590)
Net gain on sale of securities		2,363	64	2,363	64
Tax expense (benefit)		20,717	9,521	26,332	15,067
Net income		30,435	14,834	39,996	23,567
Total before tax		$ 51,152	$ 24,355	$ 66,328	$ 38,634

[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".)