Note 12 - Fair Value (Detail) - Carrying Value And Estimated Fair Values Of Financial Instruments (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010	Sep. 30, 2009
Financial Assets
Cash and cash equivalents	$ 208,259	$ 193,609	$ 169,136	$ 151,725
Investment securities held-to-maturity	4,046
Other investments	5,880	6,484
Loans held-for-sale		1,200
Cash value of bank owned life insurance	32,115	31,427
Accrued interest receivable	4,411	4,327
Financial Liabilities
Junior subordinated debentures					36,100
Time deposits	1,259,470	1,251,575
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Financial Assets
Cash and cash equivalents	208,259	193,609
Investment securities held-to-maturity	4,046	4,046
Other investments	5,880	6,484
Loans held-for-sale		1,200
Cash value of bank owned life insurance	32,115	31,427
Accrued interest receivable	4,411	4,327
Loans held-for-investment, net	1,066,922	1,015,095
Financial Liabilities
Deposit transaction accounts	791,550	744,833
Junior subordinated debentures	36,083	36,083
Accrued interest payable	261	310
Time deposits	467,920	506,742
Other borrowings	26,000	26,315
Portion at Fair Value, Fair Value Disclosure [Member]
Financial Assets
Cash and cash equivalents	208,259	193,609
Investment securities held-to-maturity	4,610	4,536
Other investments	5,880	6,484
Loans held-for-sale		1,498
Cash value of bank owned life insurance	32,115	31,427
Accrued interest receivable	4,411	4,327
Loans held-for-investment, net	1,037,820	968,434
Financial Liabilities
Deposit transaction accounts	791,550	744,833
Junior subordinated debentures	36,083	36,083
Accrued interest payable	261	310
Time deposits	471,443	511,050
Other borrowings	25,951	26,206
Off-balance sheet financial instruments
Unfunded loan commitments, including unfunded lines of credit	252	236
Standby letters of credit	$ 64	$ 69