Nature of Business and Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) BranchOffice Segment BranchLease
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	13
Minimum collection percentage of securities required to be considered as a maturity	85.00%
Period of historical loss experience to estimate allowance for loan losses	36 months
Percentage of largest amount of tax benefits likely to realize	50.00%
Number of reportable operating segment | Segment	1
Reclassification of certain income tax effects from accumulated other comprehensive income | $	$ 1,281
Number of leases branches | BranchLease	7
Commercial Real Estate Portfolio Segment
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Period on which interest rate is adjusted	5 years
Minimum
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Percentage of loan to value ratio	65.00%
Minimum | Construction Loans
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Loan term	6 months
Minimum | Commercial Real Estate Portfolio Segment
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Loan amortization period	15 years
Balloon payments period of loan	10 years
Minimum | Commercial Portfolio Segment
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Loan term	5 years
Maximum
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Percentage of loan to value ratio	90.00%
Maximum | Construction Loans
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Loan term	2 years
Maximum | Commercial Real Estate Portfolio Segment
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Percentage of loan to value ratio	75.00%
Loan amortization period	30 years
Balloon payments period of loan	15 years
Maximum | Commercial Portfolio Segment
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Loan term	7 years
Bronx
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	4
Manhattan
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	2
Queens
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	3
Brooklyn
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	3
New York and Union City
Nature Of Business And Summary Of Significant Accounting Policies Table Of Statement [Line Items]
Number of branch banking offices	1