Note 13 - Fair Value Measurements (Detail) - Financial Instruments Carrying Amounts and Estimated Fair Values (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Financial assets:
Cash and cash equivalents - carrying amount	$ 122,265	$ 184,142	$ 53,668	$ 28,541
Investment securities - carrying amount	299,073	245,571
Nonmarketable equity securities - carrying amount	5,913	7,422
Loans held for sale - carrying amount	11,659	14,147
Loans, net of allowance - carrying amount	1,319,000	1,346,116
FDIC Indemnification asset	15,340	18,697
Accrued interest receivable - carrying amount	3,706	3,821
Financial liabilities:
Deposits - carrying amount	1,594,821	1,632,004
Swap fair value hedge - carrying amount	382	453
Borrowings - carrying amount	87,060	101,716
Contingent payable	3,003	3,003
Accrued interest payable - carrying amount	475	516
No Stated Maturity [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Financial liabilities:
Deposits - fair value	990,424	1,002,258
No Stated Maturity [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Deposits - fair value	990,424	1,002,258
No Stated Maturity [Member]
Financial liabilities:
Deposits - carrying amount	990,424	1,002,258
Stated Maturity [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Financial liabilities:
Deposits - fair value	605,705	631,289
Stated Maturity [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Deposits - fair value	605,705	631,289
Stated Maturity [Member]
Financial liabilities:
Deposits - carrying amount	604,397	629,746
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial assets:
Cash and cash equivalents - fair value	122,265	184,142
Investment securities - fair value	299,073	245,571
Nonmarketable equity securities - fair value	5,913	7,422
Loans held for sale - fair value	11,659	14,147
Loans, net of allowance - fair value	1,303,061	1,332,683
FDIC Indemnification asset	15,340	18,697
Accrued interest receivable - fair value	3,706	3,821
Financial liabilities:
Swap fair value hedge - fair value	382	453
Borrowings - fair value	86,708	101,307
Contingent payable	3,003	3,003
Accrued interest payable - fair value	475	516
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents - fair value	122,265	184,142
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Investment securities - fair value	298,658	245,156
Nonmarketable equity securities - fair value	5,913	7,422
Loans held for sale - fair value	11,659	14,147
Loans, net of allowance - fair value	8,852	11,390
Financial liabilities:
Swap fair value hedge - fair value	382	453
Borrowings - fair value	86,708	101,307
Contingent payable	3,003	3,003
Accrued interest payable - fair value	475	516
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Investment securities - fair value	415	415
Loans, net of allowance - fair value	1,294,209	1,321,293
FDIC Indemnification asset	15,340	18,697
Accrued interest receivable - fair value	$ 3,706	$ 3,821