Note 8 - Income Taxes (Detail) - Reconciliation of income tax expense at the statutory rate to the Company's actual income tax expense: (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Computed at the statutory rate (35%)	$ 14,012	$ 12,530	$ 19,051
Increase (decrease) in taxes resulting from:
State income taxes, net of federal tax benefit	1,142	883	1,542
Tax exempt interest income	(2,615)	(2,780)	(2,924)
Tax exempt earnings on BOLI	(512)	(518)	(584)
Other differences, net	304	310	229
Actual tax provision	$ 12,331	$ 10,425	$ 17,314