Note 13 - Stockholders' Equity (Details) - Amounts Reclassified Out of Accumulated Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense	$ 6,458	$ 6,024	$ 6,155	$ 4,319	$ 5,782	$ 5,988	$ 5,519	$ 4,558	$ 22,956		$ 21,847	$ 23,469
Net of tax	11,948	9,421	9,627	6,756	9,200	9,365	8,637	7,129	37,752		34,331	35,348
	18,406	15,445	15,782	11,075	14,982	15,353	14,156	11,687	60,708		56,178	58,817
OTTI charges									1,419		776	1,578
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
for sale securities:									3,021
Tax expense									(1,321)
Net of tax									1,700
Accumulated Other-than-Temporary Impairment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense									621
Net of tax									(798)
OTTI charges									(1,419)
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Actuarial Losses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense									(1,237)	[1]
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Prior Service Credits [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense									46	[1]
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense									521
Net of tax									(670)
									$ (1,191)

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 12 of the Notes to consolidatedFinancial Statements "Pension and Other Postretirement Benefit Plans").