Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	$ 307,380	$ 83,590
Less 12 Months Unrealized Losses	9,162	498
More 12 Months Fair Value	6,260	4,994
More 12 Months Unrealized Losses	1,152	856
Total Fair Value	313,640	88,584
Total Unrealized Losses	10,314	1,354
US Government-sponsored Enterprises Debt Securities [Member]
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	68,823	26,433
Less 12 Months Unrealized Losses	2,357	66
More 12 Months Fair Value	0	0
More 12 Months Unrealized Losses	0	0
Total Fair Value	68,823	26,433
Total Unrealized Losses	2,357	66
US States and Political Subdivisions Debt Securities [Member]
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	63,463	17,199
Less 12 Months Unrealized Losses	2,338	174
More 12 Months Fair Value	623	0
More 12 Months Unrealized Losses	33	0
Total Fair Value	64,086	17,199
Total Unrealized Losses	2,371	174
Residential Mortgage Backed Securities [Member]
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	174,116	39,659
Less 12 Months Unrealized Losses	4,441	256
More 12 Months Fair Value	873	0
More 12 Months Unrealized Losses	25	0
Total Fair Value	174,989	39,659
Total Unrealized Losses	4,466	256
Corporate Debt Securities [Member]
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	255	0
Less 12 Months Unrealized Losses	4	0
More 12 Months Fair Value	4,764	4,994
More 12 Months Unrealized Losses	1,094	856
Total Fair Value	5,019	4,994
Total Unrealized Losses	1,098	856
Mutual Funds And Equity Securities [Member]
Note 7 - Investment Securities (Details) - Investment Securities With Unrealized Losses Not Recognized In Income [Line Items]
Less 12 Months Fair Value	723	299
Less 12 Months Unrealized Losses	22	2
More 12 Months Fair Value	0	0
More 12 Months Unrealized Losses	0	0
Total Fair Value	723	299
Total Unrealized Losses	$ 22	$ 2