Note 14 - Financial Derivatives (Details Textual)	1 Months Ended	12 Months Ended
	May 31, 2014 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Junior Subordinated Notes	$ 119,100,000	$ 119,136,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		825,000	$ (598,000)	$ (2,397,000)
Cash [Member]
Collateral Already Posted, Aggregate Fair Value		6,900,000
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Asset, Number of Instruments Held	5
Derivative Outstanding, Notional Amount	$ 119,100,000	119,100,000
Derivative Original Maturity	10 years
Derivative, Average Fixed Interest Rate	2.61%
Derivative, Average Variable Interest Rate	0.98%
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		2,200,000	3,000,000
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Expense [Member]
Net Accrued on Interest Rate Swaps		2,300,000	2,800,000
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Outstanding, Notional Amount		$ 361,500,000	340,300,000
Derivative Original Maturity		8 years
Derivative, Average Fixed Interest Rate		4.61%
Derivative, Average Variable Interest Rate		3.82%
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		$ 938,000	1,300,000
Derivative, Notional Amount at Origination		$ 361,500,000
Derivative, Average Basis Spread on Variable Rate		3.16%
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Minimum [Member]
Derivative Original Maturity		2 years
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Expense [Member]
Net Accrued on Interest Rate Swaps		$ 3,600,000	3,300,000
Negative Fair Value [Member]
Notional Amount Of Option Contract		12,100,000	9,400,000
Open OptionContracts Fair Value		121,000	28,000
Sum Of Spot And Forward Contract Notional Amount		89,500,000	115,400,000
Negative Fair Value		3,100,000	4,100,000
Positive Fair Value [Member]
Sum Of Spot And Forward Contract Notional Amount		82,400,000	100,600,000
Positive Fair Value		$ 1,300,000	$ 3,300,000