Note 9 - Borrowed Funds (Details Textual) $ in Thousands	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Securities Sold under Agreements to Repurchase	$ 150,000	$ 350,000
Weighted Average Rate Of Securities Sold Under Agreements	2.81%	4.06%
Advances from Federal Home Loan Banks	$ 475,000	$ 350,000
Mature in March 2018 [Member]
Advances from Federal Home Loan Banks	25,000
Mature in December 2019 [Member]
Advances from Federal Home Loan Banks	$ 50,000
Over-night Borrowings [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	1.09%	0.55%
Advances from Federal Home Loan Banks	$ 400,000	$ 275,000
Non Overnight Borrowings [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	1.48%
Advances from Federal Home Loan Banks	$ 75,000
Securities Sold under Agreements to Repurchase [Member]
Investment Securities Pledged As Collateral	165,000	$ 372,000
Non Callable Fixed Rate Securities [Member]
Securities Sold under Agreements to Repurchase	$ 150,000
Weighted Average Rate Of Securities Sold Under Agreements	2.81%
Number Of Securities Sold Under Agreements To Repurchase	3
Non Callable Fixed Rate Securities [Member] \| Mature in August 2016 [Member]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 50,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	50,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	$ 50,000

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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