Note 9 - Accumulated Other Comprehensive Income (Detail) - Tax Effects Allocated to Each Component of Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Before Tax Amount	$ 955	$ 1,136	$ 1,701	$ 2,800
Tax Expense (Benefit)	344	409	613	1,008
Net of Tax Amount	611	727	1,088	1,792
Change in Accumulated Gain (Loss) on Effective Cash Flow Derivatives [Member]
Before Tax Amount	12	(464)	65	(608)
Tax Expense (Benefit)	4	(167)	23	(219)
Net of Tax Amount	8	(297)	42	(389)
Securities With OTTI Charges During the Period [Member]
Before Tax Amount	(14)	(32)	(101)	(215)
Tax Expense (Benefit)	(5)	(11)	(36)	(77)
Net of Tax Amount	(9)	(21)	(65)	(138)
OTTI Charges Recognized in Net Income [Member]
Before Tax Amount	(7)	(30)	(84)	(195)
Tax Expense (Benefit)	(3)	(10)	(30)	(70)
Net of Tax Amount	(4)	(20)	(54)	(125)
Net Unrealized Losses On Investment Securities With OTTI [Member]
Before Tax Amount			(17)	(20)
Tax Expense (Benefit)			(6)	(7)
Net of Tax Amount			(11)	(13)
Unrealized Holding Gain Arising During the Period [Member]
Before Tax Amount	974	1,805	1,761	3,557
Tax Expense (Benefit)	351	650	635	1,280
Net of Tax Amount	623	1,155	1,126	2,277
Reclassification Adjustment for Gain (Loss) Included in Net Income [Member]
Before Tax Amount	24	203	108	129
Tax Expense (Benefit)	9	73	39	46
Net of Tax Amount	15	130	69	83
Net Unrealized Gains on Investment Securities [Member]
Before Tax Amount	950	1,602	1,653	3,428
Tax Expense (Benefit)	342	577	596	1,234
Net of Tax Amount	$ 608	$ 1,025	$ 1,057	$ 2,194