Note 8 - Goodwill and Other Intangible Assets (Detail) - Core Deposit Intangibles (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Balance at beginning of year	$ 42,832	$ 36,591	$ 35,731
Balance at beginning of year	22,276	17,998	14,069
Balance at beginning of year	20,556	18,593	21,662
Additions	1,419	6,242	860
Additions	1,419	6,242	860
Amortization expense	3,802	4,279	3,929
Amortization expense	(3,802)	(4,279)	(3,929)
Fully amortized assets/other	(9,933)	(1)
Fully amortized assets/other	(9,933)	(1)
Balance at end of year	34,318	42,832	36,591
Balance at end of year	16,145	22,276	17,998
Balance at end of year	$ 18,173	$ 20,556	$ 18,593
Weighted-average remaining life (in years)	6.9	7.3	7.0