Note 14 - Financial Derivatives (Details Textual) - USD ($)		3 Months Ended		6 Months Ended
	May 31, 2014	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Junior Subordinated Notes	$ 119,100,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		$ (550,000)	$ (1,282,000)	$ (251,000)	$ (4,402,000)
Cash [Member]
Collateral Already Posted, Aggregate Fair Value		7,000,000		7,000,000
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Original Maturity	10 years
Derivative, Average Fixed Interest Rate	2.61%
Derivative, Average Variable Interest Rate	1.26%
Derivative Outstanding, Notional Amount	$ 119,100,000	119,100,000		119,100,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax				2,400,000
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Expense [Member]
Net Accrued on Interest Rate Swaps		$ 439,000	593,000	$ 900,000	1,200,000
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative, Average Fixed Interest Rate		4.57%		4.57%
Derivative, Average Basis Spread on Variable Rate		2.98%		2.98%
Derivative, Average Variable Interest Rate		4.07%		4.07%
Derivative Outstanding, Notional Amount		$ 446,100,000		$ 446,100,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax				1,000,000
Net Accrued on Interest Rate Swaps		651,000	$ 946,000	$ 1,400,000	$ 1,900,000
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Minimum [Member]
Derivative Original Maturity				4 years
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Maximum [Member]
Derivative Original Maturity				8 years
Negative Fair Value [Member]
Negative Fair Value		640,000		$ 640,000		$ 3,100,000
Notional Amount Of Option Contract		13,600,000		13,600,000		12,100,000
Open OptionContracts Fair Value		231,000		231,000		121,000
Sum Of Spot And Forward Contract Notional Amount		45,900,000		45,900,000		89,500,000
Positive Fair Value [Member]
Positive Fair Value		2,400,000		2,400,000		1,300,000
Sum Of Spot And Forward Contract Notional Amount		$ 157,500,000		$ 157,500,000		$ 82,400,000