Note 10 - Fair Value of Financial Instruments - Carrying Amounts and Estimated Fair Values of Selected Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Other securities	$ 28,217	$ 29,699
Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	(390)	3,728
Interest rate swaps	449	3,758
Reported Value Measurement [Member]
Cash and due from banks	45,094	51,546
Mortgage-backed securities	7,958	7,973
Other securities	23,207	22,913
Mortgage-backed securities	528,119	509,650
Other securities	232,913	228,704
Loans	5,380,062	5,176,999
FHLB-NY stock	54,942	60,089
Accrued interest receivable	24,673	21,405
Deposits	4,716,315	4,383,278
Liabilities, Fair Value	1,197,101	1,309,653
Accrued interest payable	6,732	2,659
Reported Value Measurement [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	32,600	7,388
Interest rate swaps	449	3,758
Estimate of Fair Value Measurement [Member]
Cash and due from banks	45,094	51,546
Mortgage-backed securities	7,221	7,810
Other securities	20,996	21,889
Mortgage-backed securities	528,119	509,650
Other securities	232,913	228,704
Loans	5,301,783	5,169,108
FHLB-NY stock	54,942	60,089
Accrued interest receivable	24,673	21,405
Deposits	4,706,114	4,380,174
Liabilities, Fair Value	1,184,589	1,310,487
Accrued interest payable	6,732	2,659
Estimate of Fair Value Measurement [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	32,600	7,388
Interest rate swaps	449	3,758
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	45,094	51,546
Mortgage-backed securities
Other securities
Mortgage-backed securities
Other securities	11,405	11,575
Loans
FHLB-NY stock
Accrued interest receivable	5	16
Deposits	3,153,353	3,031,345
Liabilities, Fair Value
Accrued interest payable
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount
Interest rate swaps
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and due from banks
Mortgage-backed securities	7,221	7,810
Other securities
Mortgage-backed securities	528,119	509,650
Other securities	220,303	216,019
Loans
FHLB-NY stock	54,942	60,089
Accrued interest receivable	1,962	1,916
Deposits	1,552,761	1,348,829
Liabilities, Fair Value	1,144,438	1,273,501
Accrued interest payable	6,732	2,659
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	32,600	7,388
Interest rate swaps	449	3,758
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and due from banks
Mortgage-backed securities
Other securities	20,996	21,889
Mortgage-backed securities
Other securities	1,205	1,110
Loans	5,301,783	5,169,108
FHLB-NY stock
Accrued interest receivable	22,706	19,473
Deposits
Liabilities, Fair Value	40,151	36,986
Accrued interest payable
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount
Interest rate swaps

Fair value portion of accrued interest payable.

No definition available.

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Fair value portion of accrued interest receivable.

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No definition available.

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This element represents the portion of the balance sheet assertion valued at fair value pursuant to the fair value option by the entity. Additionally, this element may be used in connection with the fair value option disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities, except for mortgage-backed securities, neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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No definition available.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

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No definition available.

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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as held-to-maturity.

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