Long-Term Debt and FHLBNY Stock (Detail Textuals) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Subordinated Debt
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rate	4.31%	3.454%
Interest rate, description	3-month LIBOR plus 2.00
Interest LIBOR rate	2.00%
Subordinated debt securities	$ 5,155
Stated maturity date	May 23, 2035
Subordinated Debt \| RSB Capital Trust I
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rate, description	3-month LIBOR plus 2.00
Interest LIBOR rate	2.00%
Trust term	30 years
FHLBNY
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Preapproved secured line of credit	$ 409,776	$ 370,974
Amount of pledged assets	148,006	25,608
Outstanding amount secured line of credit	$ 17,500	$ 14,500
Interest rate	2.38%	1.53%
Unsecured, uncommitted line of credit	$ 10,000
Structured borrowings	$ 36,121

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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- Definition

Amount of advances from the Federal Home Loan Bank (FHLB).

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Average amount borrowed under the credit facility during the period.

+ References

No definition available.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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- Definition

Period between issuance and maturity of long-term debt, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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