Note 10 - Fair Value Measurements (Details) - Fair Values of Financial Instruments (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Assets
Carrying Value-Cash and due from banks	$ 8,602,000	$ 9,577,000	$ 7,765,000
Fair Value-Cash and due from banks	8,602,000	9,577,000
Carrying Value Federal funds sold	9,480,000	5,695,000	10,634,000
Fair Value Federal funds sold	9,480,000	5,695,000	10,634,000
Carrying Value Interest bearing deposits with other banks	97,400,000	291,688,000	172,849,000
Fair Value Interest bearing deposits with other banks	97,400,000	291,688,000	172,849,000
Carrying Value Investment securities	378,990,000	378,133,000	335,779,000
Fair Value Investment securities	378,990,000	378,133,000	335,779,000
Carrying Value Federal Reserve and Federal Home Loan Bank stock	10,626,000	11,272,000
Fair Value Federal Reserve and Federal Home Loan Bank stock	10,626,000	11,272,000
Carrying Value Loans held for sale	35,411,000	42,030,000	104,767,000
Fair Value Loans held for sale	35,411,000	42,030,000
Carrying Value Loans	3,279,429,000	2,945,158,000	2,691,358,000
Fair Value Loans	3,312,300,000	2,979,180,000
Carrying Value Bank owned life insurance	40,361,000	39,738,000	29,324,000
Fair Value Bank owned life insurance	40,361,000	39,738,000	29,324,000
Carrying Value Annuity investment	11,196,000	11,227,000
Fair Value Annuity investment	11,196,000	11,227,000
Derivative assets	223,000		0
Derivative assets	223,000		0
Liabilities
Carrying Value Noninterest bearing deposits	3,367,927,000	3,225,414,000	2,888,236,000
Carrying Value Borrowings	99,946,000	119,771,000
Fair Value Borrowings	101,019,000	120,764,000
Derivative liabilites	159,000		0
Derivative liabilites	159,000		0
Fair Value, Inputs, Level 1 [Member]
Assets
Carrying Value Investment securities	168,000	165,000
Fair Value Investment securities	168,000	165,000
Fair Value, Inputs, Level 2 [Member]
Assets
Fair Value-Cash and due from banks	8,602,000	9,577,000
Carrying Value Federal funds sold	9,480,000	5,695,000
Fair Value Federal funds sold	9,480,000	5,695,000
Carrying Value Interest bearing deposits with other banks	97,400,000	291,688,000
Fair Value Interest bearing deposits with other banks	97,400,000	291,688,000
Carrying Value Investment securities	378,603,000	377,749,000
Fair Value Investment securities	378,603,000	377,749,000
Fair Value Federal Reserve and Federal Home Loan Bank stock	10,626,000	11,272,000
Fair Value Loans held for sale	35,411,000	42,030,000
Fair Value Loans	4,786,000	14,249,000
Carrying Value Bank owned life insurance	40,361,000	39,738,000
Fair Value Bank owned life insurance	40,361,000	39,738,000
Carrying Value Annuity investment	11,196,000	11,227,000
Fair Value Annuity investment	11,196,000	11,227,000
Liabilities
Fair Value Borrowings	101,019,000	120,764,000
Fair Value, Inputs, Level 2 [Member] | Noninterest-bearing Deposits [Member]
Liabilities
Fair Value Noninterest bearing deposits	945,485,000	849,409,000
Fair Value, Inputs, Level 2 [Member] | Interest-bearing Deposits [Member]
Liabilities
Fair Value Noninterest bearing deposits	2,422,032,000	2,375,861,000
Fair Value, Inputs, Level 3 [Member]
Assets
Carrying Value Investment securities	219,000	219,000
Fair Value Investment securities	219,000	219,000
Fair Value Loans	3,307,514,000	2,964,931,000
Derivative assets	223,000
Derivative assets	223,000
Liabilities
Derivative liabilites	159,000
Derivative liabilites	159,000
Noninterest-bearing Deposits [Member]
Liabilities
Carrying Value Noninterest bearing deposits	945,485,000	849,409,000
Fair Value Noninterest bearing deposits	945,485,000	849,409,000
Interest-bearing Deposits [Member]
Liabilities
Carrying Value Noninterest bearing deposits	2,422,442,000	2,376,005,000
Fair Value Noninterest bearing deposits	$ 2,422,032,000	$ 2,375,861,000