Note 20 - Regulatory Matters - Risk Based Capital Amounts and Ratios (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Subsidiaries [Member]
Total risk-based capital, actual amount	[1]	$ 319,526	$ 298,129
Total risk-based capital, actual ratio	[1]	12.64%	12.91%
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 202,232	$ 184,743
Total risk-based capital, minimum for adequately capitalized ratio	[1]	8.00%	8.00%
Total risk-based capital, minimum for well capitalized amount	[1]	$ 252,790	$ 230,929
Total risk-based capital, minimum for well capitalized ratio	[1]	10.00%	10.00%
Common Equity Tier 1 risk-based capital, actual amount		$ 294,815	$ 275,256
Common Equity Tier 1 risk-based capital, actual ratio		11.66%	11.92%
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 113,779	$ 103,914
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio		4.50%	4.50%
Common Equity Tier 1 risk-based capital, minimum for well capitalized amount		$ 151,706	$ 138,552
Common Equity Tier 1 risk-based capital, minimum for well capitalized ratio		6.00%	6.00%
Tier 1 risk-based capital, actual amount	[1]	$ 294,815	$ 275,256
Tier 1 risk-based capital, actual ratio	[1]	11.66%	11.92%
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 151,706	$ 138,552
Tier 1 risk-based capital, minimum for adequately capitalized ratio	[1]	6.00%	6.00%
Tier 1 risk-based capital, minimum for well capitalized amount	[1]	$ 151,706	$ 138,552
Tier 1 risk-based capital, minimum for well capitalized ratio	[1]	6.00%	6.00%
Leverage, actual amount	[2]	$ 294,815	$ 275,256
Leverage, actual ratio	[2]	10.26%	10.19%
Leverage, minimum for adequately capitalized amount	[2]	$ 114,938	$ 108,049
Leverage, minimum for adequately capitalized ratio	[2]	4.00%	4.00%
Leverage, minimum for well capitalized amount	[2]	$ 143,672	$ 135,062
Leverage, minimum for well capitalized ratio	[2]	5.00%	5.00%
Total risk-based capital, actual amount	[1]	$ 330,597	$ 307,666
Total risk-based capital, actual ratio	[1]	13.05%	13.31%
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 202,665	$ 184,923
Total risk-based capital, minimum for adequately capitalized ratio	[1]	8.00%	8.00%
Common Equity Tier 1 risk-based capital, actual amount		$ 305,886	$ 284,793
Common Equity Tier 1 risk-based capital, actual ratio		12.07%	12.32%
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 114,042	$ 104,023
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio		4.50%	4.50%
Tier 1 risk-based capital, actual amount	[1]	$ 305,886	$ 284,793
Tier 1 risk-based capital, actual ratio	[1]	12.07%	12.32%
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 152,056	$ 138,698
Tier 1 risk-based capital, minimum for adequately capitalized ratio	[1]	6.00%	6.00%
Leverage, actual amount	[2]	$ 305,886	$ 284,793
Leverage, actual ratio	[2]	10.63%	10.53%
Leverage, minimum for adequately capitalized amount	[2]	$ 115,103	$ 108,183
Leverage, minimum for adequately capitalized ratio	[2]	4.00%	4.00%

[1] Ratio is computed in relation to risk-weighted assets.

[2] Ratio is computed in relation to average assets.