Note 9 - Securities Sold Under Agreements to Repurchase (Detail) - Securities Sold Under Agreements to Repurchase (Non-Callable Fixed Rate Securities Sold Under Agreements to Repurchase [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013
No. of Agreements	4
Amount (in Dollars)	$ 200,000
Weighted Average Interest Rate	2.78%
Maturing in Three to Five Years [Member]
No. of Agreements	2
Amount (in Dollars)	100,000
Weighted Average Interest Rate	2.71%
Maturing in More Than Five Years [Member]
No. of Agreements	2
Amount (in Dollars)	$ 100,000
Weighted Average Interest Rate	2.86%