Note 18 - Fair Value of Financial Instruments - Carrying Amounts and Estimated Fair Values of Selected Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Securities held-to-maturity, amortized cost	$ 32,018	$ 30,886
Securities available for sale, fair value	822,655	738,354
Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	1,001	3,728
Interest rate swaps	2,239	3,758
Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost	7,953	7,973
Securities available for sale, fair value	557,953	509,650
Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost	24,065	22,913
Securities available for sale, fair value	264,702	228,704
Reported Value Measurement [Member]
Cash and due from banks	118,561	51,546
Loans	5,551,484	5,176,999
FHLB-NY stock	57,282	60,089
Accrued interest receivable	25,485	21,405
Deposits	4,960,784	4,383,278
Borrowings	1,250,843	1,309,653
Accrued interest payable	5,890	2,659
Reported Value Measurement [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	15,961	7,388
Interest rate swaps	2,239	3,758
Reported Value Measurement [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost	7,953	7,973
Securities available for sale, fair value	557,953	509,650
Reported Value Measurement [Member] \| Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost	24,065	22,913
Securities available for sale, fair value	264,702	228,704
Estimate of Fair Value Measurement [Member]
Cash and due from banks	118,561	51,546
Loans	5,496,266	5,169,108
FHLB-NY stock	57,282	60,089
Accrued interest receivable	25,485	21,405
Deposits	4,955,077	4,380,174
Borrowings	1,241,745	1,310,487
Accrued interest payable	5,890	2,659
Estimate of Fair Value Measurement [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	15,961	7,388
Interest rate swaps	2,239	3,758
Estimate of Fair Value Measurement [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost	7,366	7,810
Securities available for sale, fair value	557,953	509,650
Estimate of Fair Value Measurement [Member] \| Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost	22,508	21,889
Securities available for sale, fair value	264,702	228,704
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	118,561	51,546
Loans
FHLB-NY stock
Accrued interest receivable	54	16
Deposits	3,397,474	3,031,345
Borrowings
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 1 [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost
Securities available for sale, fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost
Securities available for sale, fair value	11,586	11,575
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and due from banks
Loans
FHLB-NY stock	57,282	60,089
Accrued interest receivable	2,756	1,916
Deposits	1,557,603	1,348,829
Borrowings	1,199,896	1,273,501
Accrued interest payable	5,890	2,659
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Rate Swap [Member]
Interest Rate Swaps, Net Amount	15,961	7,388
Interest rate swaps	2,239	3,758
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost	7,366	7,810
Securities available for sale, fair value	557,953	509,650
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost
Securities available for sale, fair value	251,860	216,019
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and due from banks
Loans	5,496,266	5,169,108
FHLB-NY stock
Accrued interest receivable	22,675	19,473
Deposits
Borrowings	41,849	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
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Collateralized Mortgage Backed Securities [Member]
Securities held-to-maturity, amortized cost
Securities available for sale, fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Other Debt Obligations [Member]
Securities held-to-maturity, amortized cost	22,508	21,889
Securities available for sale, fair value	$ 1,256	$ 1,110

Fair value portion of accrued interest payable.

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Fair value portion of accrued interest receivable.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (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.

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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.

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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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Amount 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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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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