Note 3 - Securities (Detail) - Changes in Credit Losses Recognized in Earnings (USD $) In Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2010	Jun. 30, 2010	Mar. 31, 2011 Balance Beginning OfPeriod [Member]	Dec. 31, 2010 Balance Beginning OfPeriod [Member]	Mar. 31, 2010 Balance Beginning OfPeriod [Member]	Dec. 31, 2009 Balance Beginning OfPeriod [Member]	Jun. 30, 2011 Balance End OfPeriod [Member]	Jun. 30, 2010 Balance End OfPeriod [Member]
Cumulative amount recognized at beginning of period			$ 35,589	$ 35,589	$ 33,709	$ 30,946	$ 35,589	$ 34,843
Losses recognized on securities that previously had credit losses	1,048	3,568
Losses recognized on securities that did not previously have credit losses	86	329
Cumulative amount recognized at end of period			$ 35,589	$ 35,589	$ 33,709	$ 30,946	$ 35,589	$ 34,843