Note 3 - Securities (Detail) - Securities In An Unrealized Loss Position (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Number of Securities	83	62
Less than 12 Months Fair Value	$ 192,760	$ 167,092
Less than 12 months Unrealized Losses	1,099	1,848
12 Months or Longer Fair Value	29,584	39,986
12 Months or Longer Unrealized Losses	36,024	36,288
Continuous Unrealized Loss Position Fair Value	222,344	207,078
Continuous Unrealized Loss Position Unrealized Losses	37,123	38,136
US Government Corporations and Agencies Securities [Member]
Number of Securities	1	2
Less than 12 Months Fair Value	2,006
Less than 12 months Unrealized Losses	5
12 Months or Longer Fair Value		5,035
12 Months or Longer Unrealized Losses		25
Continuous Unrealized Loss Position Fair Value	2,006	5,035
Continuous Unrealized Loss Position Unrealized Losses	5	25
Collateralized Residential Mortgage Obligations [Member]
Number of Securities	36	30
Less than 12 Months Fair Value	159,149	163,819
Less than 12 months Unrealized Losses	887	1,818
12 Months or Longer Fair Value	14,875	12,628
12 Months or Longer Unrealized Losses	427	528
Continuous Unrealized Loss Position Fair Value	174,024	176,447
Continuous Unrealized Loss Position Unrealized Losses	1,314	2,346
Other Residential Mortgage-Backed Securities [Member]
Number of Securities	4	4
Less than 12 Months Fair Value	8,630	182
Less than 12 months Unrealized Losses	16	17
12 Months or Longer Fair Value	262	1,072
12 Months or Longer Unrealized Losses	16	6
Continuous Unrealized Loss Position Fair Value	8,892	1,254
Continuous Unrealized Loss Position Unrealized Losses	32	23
State and Municipal [Member]
Number of Securities	36	19
Less than 12 Months Fair Value	22,975	934
Less than 12 months Unrealized Losses	191	2
12 Months or Longer Fair Value	3,365	7,857
12 Months or Longer Unrealized Losses	30	364
Continuous Unrealized Loss Position Fair Value	26,340	8,791
Continuous Unrealized Loss Position Unrealized Losses	221	366
Collateralized Debt Obligations [Member]
Number of Securities	6	6
12 Months or Longer Fair Value	11,082	13,394
12 Months or Longer Unrealized Losses	35,551	35,365
Continuous Unrealized Loss Position Fair Value	11,082	13,394
Continuous Unrealized Loss Position Unrealized Losses	35,551	35,365
Corporate Debt Securities [Member]
Number of Securities		1
Less than 12 Months Fair Value		2,157
Less than 12 months Unrealized Losses		11
Continuous Unrealized Loss Position Fair Value		2,157
Continuous Unrealized Loss Position Unrealized Losses		$ 11