Note 15 - Fair Value Measurements and Fair Value of Financial Instruments - Quantitative Information about Level 3 Assets (Details) $ in Thousands		Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Valuation Technique, Discounted Cash Flow [Member] | Corporate Debt Securities [Member]
Fair Value		$ 3,069	$ 3,086
Valuation Technique, Discounted Cash Flow [Member] | Corporate Debt Securities [Member] | Measurement Input, Discount Rate [Member]
Securities, unobservable input		(0.0824)	(0.0599)
Valuation Technique, Discounted Cash Flow [Member] | SBA Servicing Assets [Member]
Fair Value		$ 4,785	$ 5,243
Valuation Technique, Discounted Cash Flow [Member] | SBA Servicing Assets [Member] | Measurement Input, Discount Rate [Member]
SBA servicing assets, unobservable input		(0.115)	(0.105)
Valuation Technique, Discounted Cash Flow [Member] | SBA Servicing Assets [Member] | Measurement Input, Prepayment Rate [Member]
SBA servicing assets, unobservable input		(0.1031)	(0.0785)
Valuation Technique, Discounted Cash Flow [Member] | Collateralized Debt Obligations [Member]
Fair Value			$ 489
Valuation Technique, Discounted Cash Flow [Member] | Collateralized Debt Obligations [Member] | Measurement Input, Discount Rate [Member]
Securities, unobservable input			(0.0833)
Valuation, Market Approach [Member] | Impaired Loans [Member]
Fair Value	[1]	$ 5,955	$ 7,322
Valuation, Market Approach [Member] | Impaired Loans [Member] | Measurement Input, Liquidation Expenses [Member] | Minimum [Member]
Impaired loans, unobservable input	[2],[3]	0.11	0.1
Valuation, Market Approach [Member] | Impaired Loans [Member] | Measurement Input, Liquidation Expenses [Member] | Maximum [Member]
Impaired loans, unobservable input	[2],[3]	0.24	0.21
Valuation, Market Approach [Member] | Impaired Loans [Member] | Measurement Input, Liquidation Expenses [Member] | Weighted Average [Member]
Impaired loans, unobservable input	[3]	(0.13)	(0.14)
Appraised Value of Collateral [Member] | Other Real Estate Owned [Member]
Fair Value	[1]	$ 1,114
Appraised Value of Collateral [Member] | Other Real Estate Owned [Member] | Measurement Input, Liquidation Expenses [Member] | Minimum [Member]
Other real estate owned, unobservable input	[2],[3]		0.04
Appraised Value of Collateral [Member] | Other Real Estate Owned [Member] | Measurement Input, Liquidation Expenses [Member] | Maximum [Member]
Other real estate owned, unobservable input	[2],[3]	(0.07)	0.07
Appraised Value of Collateral [Member] | Other Real Estate Owned [Member] | Measurement Input, Liquidation Expenses [Member] | Weighted Average [Member]
Other real estate owned, unobservable input	[2],[3]		(0.07)
Sales Price Valuation Technique [Member] | Other Real Estate Owned [Member]
Fair Value			$ 5,727
Sales Price Valuation Technique [Member] | Other Real Estate Owned [Member] | Measurement Input, Liquidation Expenses [Member]
Other real estate owned, unobservable input	[2],[3]		(0.22)

[1] Fair value is generally determined through independent appraisals of the underlying collateral, which include Level 3 inputs that are not identifiable.

[2] Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses.

[3] The range and weighted average of qualitative factors such as economic conditions and estimated liquidation expenses are presented as a percent of the appraised value.