Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	$ 195,517	$ 81,274
Less than 12 Months, Unrealized Losses	1,617	254
12 Months or More, Fair Value	56,654	159,818
12 Months or More, Unrealized Losses	1,618	2,750
Total, Fair Value	252,171	241,092
Total, Unrealized Losses	3,235	3,004
US Government-sponsored Enterprises Debt Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	50,661	22,696
Less than 12 Months, Unrealized Losses	378	76
12 Months or More, Fair Value	19,648	60,892
12 Months or More, Unrealized Losses	254	939
Total, Fair Value	70,309	83,588
Total, Unrealized Losses	632	1,015
US States and Political Subdivisions Debt Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	47,962	20,746
Less than 12 Months, Unrealized Losses	538	81
12 Months or More, Fair Value	8,103	21,272
12 Months or More, Unrealized Losses	143	316
Total, Fair Value	56,065	42,018
Total, Unrealized Losses	681	397
Residential Mortgage Backed Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	93,303	37,451
Less than 12 Months, Unrealized Losses	662	82
12 Months or More, Fair Value	23,454	71,311
12 Months or More, Unrealized Losses	699	1,117
Total, Fair Value	116,757	108,762
Total, Unrealized Losses	1,361	1,199
Commercial Mortgage Backed Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	2,739	0
Less than 12 Months, Unrealized Losses	14	0
12 Months or More, Fair Value	0	723
12 Months or More, Unrealized Losses	0	10
Total, Fair Value	2,739	723
Total, Unrealized Losses	14	10
Corporate Debt Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	287	76
Less than 12 Months, Unrealized Losses	5	4
12 Months or More, Fair Value	5,379	5,525
12 Months or More, Unrealized Losses	509	354
Total, Fair Value	5,666	5,601
Total, Unrealized Losses	514	358
Mutual Funds and Equity Securities [Member]
Note 6 - Investment Securities (Details) - Investment Securities with Unrealized Losses Not Recognized in Income [Line Items]
Less than 12 Months, Fair Value	565	305
Less than 12 Months, Unrealized Losses	20	11
12 Months or More, Fair Value	70	95
12 Months or More, Unrealized Losses	13	14
Total, Fair Value	635	400
Total, Unrealized Losses	$ 33	$ 25