Note 5 - Fair Value Measurements and Fair Values of Financial Instruments (Details) - Assets Measured at Fair Value (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	$ 470,068		$ 472,577
Nonrecurring fair value measurements
Foreclosed assets held for sale	890		879
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	47,970		31,217
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	47,970		31,217
Obligations of States and Political Subdivisions, Tax-exempt [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Obligations of States and Political Subdivisions, Tax-exempt [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	134,483		137,020
Obligations of States and Political Subdivisions, Tax-exempt [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Obligations of States and Political Subdivisions, Tax-exempt [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	134,483		137,020
Obligations of States and Political Subdivisions, Tax-exempt [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	134,483		137,020
Obligations of States and Political Subdivisions, Taxable [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Obligations of States and Political Subdivisions, Taxable [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	29,689		24,817
Obligations of States and Political Subdivisions, Taxable [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Obligations of States and Political Subdivisions, Taxable [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	29,689		24,817
Obligations of States and Political Subdivisions, Taxable [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	29,689		24,817
Mortgage-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Mortgage-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	65,625		80,196
Mortgage-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Mortgage-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	65,625		80,196
Mortgage-backed Securities [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	65,625		80,196
Collateralized Mortgage Obligations, Issued by U.S. Government Agencies [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Collateralized Mortgage Obligations, Issued by U.S. Government Agencies [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	182,924		183,510
Collateralized Mortgage Obligations, Issued by U.S. Government Agencies [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Collateralized Mortgage Obligations, Issued by U.S. Government Agencies [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	182,924		183,510
Collateralized Mortgage Obligations, Issued by U.S. Government Agencies [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	182,924		183,510
Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0
Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	660
Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0
Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	660
Collateralized Debt Obligations [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	660
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	461,351		462,591
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		1,613
Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	461,351		464,204
Debt Securities [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	461,351		464,204
Marketable Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	8,717		8,373
Marketable Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Marketable Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		0
Marketable Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	8,717		8,373
Marketable Equity Securities [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	8,717		8,373
Trust Preferred Securities Issued by Individual Institutions [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Trust Preferred Securities Issued by Individual Institutions [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			5,171
Trust Preferred Securities Issued by Individual Institutions [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Trust Preferred Securities Issued by Individual Institutions [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			5,171
Trust Preferred Securities Issued by Individual Institutions [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			5,171
Collateralized Debt Obligations, Pooled Trust Preferred Securities - Senior Tranches [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Collateralized Debt Obligations, Pooled Trust Preferred Securities - Senior Tranches [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Collateralized Debt Obligations, Pooled Trust Preferred Securities - Senior Tranches [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			1,613
Collateralized Debt Obligations, Pooled Trust Preferred Securities - Senior Tranches [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			1,613
Collateralized Debt Obligations, Pooled Trust Preferred Securities - Senior Tranches [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			1,613
Other Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Other Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			660
Other Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			0
Other Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities			660
Other Collateralized Debt Obligations [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities		660
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	8,717		8,373
Servicing rights	0		0
Total recurring fair value measurements	8,717		8,373
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	461,351		462,591
Servicing rights	0		0
Total recurring fair value measurements	461,351		462,591
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	0		1,613
Servicing rights	850		605
Total recurring fair value measurements	850		2,218
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
AVAILABLE-FOR-SALE SECURITIES:
Available-for-sale securities	470,068		472,577
Servicing rights	850		605
Total recurring fair value measurements	470,918		473,182
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Nonrecurring fair value measurements
Impaired loans with a valuation allowance	0		0
Valuation allowance	0		0
Impaired loans, net	0		0
Foreclosed assets held for sale	0		0
Total nonrecurring fair value measurements	0		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Nonrecurring fair value measurements
Impaired loans with a valuation allowance	0		0
Valuation allowance	0		0
Impaired loans, net	0		0
Foreclosed assets held for sale	0		0
Total nonrecurring fair value measurements	0		0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Nonrecurring fair value measurements
Impaired loans with a valuation allowance	1,874		2,710
Valuation allowance	(762)		(623)
Impaired loans, net	1,112		2,087
Foreclosed assets held for sale	890		879
Total nonrecurring fair value measurements	2,002		2,966
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member]
Nonrecurring fair value measurements
Impaired loans with a valuation allowance	1,874		2,710
Valuation allowance	(762)		(623)
Impaired loans, net	1,112		2,087
Foreclosed assets held for sale	890		879
Total nonrecurring fair value measurements	2,002		2,966
Fair Value, Inputs, Level 3 [Member]
AVAILABLE-FOR-SALE SECURITIES:
Total recurring fair value measurements	$ 850	$ 2,397	$ 2,218	$ 3,992	$ 5,829	$ 5,743