Note 9 - Securities Sold Under Agreements to Repurchase (Detail) - Securities Sold Under Agreements to Repurchase (USD $)	6 Months Ended
	Jun. 30, 2012
No. of agreements	27
Amount (in Dollars)	$ 1,400,000
Weighted average rate	4.09%
Fixed to Floating One Hundred and Fifty Million With Three Agreements At Three Point Seven Nine Percent [Member]
Maximum rate	3.79%
Minimum rate	0.00%
No. of agreements	3
Amount (in Dollars)	150,000
Weighted average rate	3.78%
Final maturity	2,014
Fixed To Floating Fifty Million With One Agreement At Three Point Five Three Percent Member
Maximum rate	3.53%
Minimum rate	0.00%
No. of agreements	1
Amount (in Dollars)	50,000
Weighted average rate	3.53%
Final maturity	2,014
Fixed To Floating Two Hundred Million Member
Maximum rate	3.50%
Minimum rate	0.00%
No. of agreements	4
Amount (in Dollars)	200,000
Weighted average rate	3.50%
Final maturity	2,014
Fixed To Floating One Hundred And Fifty Million With Three Agreements At Three Point Five Percent Member
Maximum rate	3.50%
Minimum rate	0.00%
No. of agreements	3
Amount (in Dollars)	150,000
Weighted average rate	3.50%
Final maturity	2,015
Fixed to Floating Fifty Million at Three Point Five Three Percent Maturing in 2015 [Member]
Maximum rate	3.53%
Minimum rate	0.00%
No. of agreements	1
Amount (in Dollars)	50,000
Weighted average rate	3.53%
Final maturity	2,015
Fixed To Floating Fifty Million With One Agreement At Three Point Two Five Percent Member
Maximum rate	3.25%
Minimum rate	0.00%
No. of agreements	1
Amount (in Dollars)	50,000
Weighted average rate	3.25%
Final maturity	2,015
Floating to Fixed Four Hundred and Fifty Million [Member]
No. of agreements	8
Amount (in Dollars)	450,000
Weighted average rate	4.58%
Final maturity	2,014
Floating To Fixed Two Hundred Million Member
No. of agreements	4
Amount (in Dollars)	200,000
Weighted average rate	5.00%
Final maturity	2,017
Fixed Non-Callable [Member]
No. of agreements	2
Amount (in Dollars)	$ 100,000
Weighted average rate	3.58%
Final maturity	2,018