Fair Value Measurements - Estimated Fair Values of the Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financial assets:
Trading securities	$ 11,504	$ 10,751
Debt securities available-for-sale	743,699	952,173
Debt securities held-to-maturity	9,371	10,389
Loans held-for-sale	950
Financial liabilities:
Subordinated debentures, net of issuance costs	61,163	60,996
Investment measured at fair value	10,300	10,100
Carrying Value
Financial assets:
Cash and cash equivalents	80,556	45,799
Trading securities	11,504	10,751
Debt securities available-for-sale	743,699	952,173
Debt securities held-to-maturity	10,114	10,760
Equity securities	348	361
FHLBNY stock, at cost	41,165	30,382
Loans held-for-sale	950
Net loans held-for-investment	4,191,494	4,201,076
Derivative assets	6,515	5,321
Financial liabilities:
Deposits	3,668,513	4,150,219
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	918,973	583,859
Subordinated debentures, net of issuance costs	61,163	60,996
Advance payments by borrowers for taxes and insurance	25,968	25,995
Derivative liabilities	6,516	5,321
Estimated Fair Value
Financial assets:
Cash and cash equivalents	80,556	45,799
Trading securities	11,504	10,751
Debt securities available-for-sale	743,699	952,173
Debt securities held-to-maturity	9,371	10,389
Equity securities	348	361
FHLBNY stock, at cost	41,165	30,382
Net loans held-for-investment	3,942,539	4,016,849
Derivative assets	6,515	5,321
Financial liabilities:
Deposits	3,669,988	4,148,938
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	850,551	564,588
Subordinated debentures, net of issuance costs	45,196	54,393
Advance payments by borrowers for taxes and insurance	25,968	25,995
Derivative liabilities	6,516	5,321
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	80,556	45,799
Trading securities	11,504	10,751
Debt securities available-for-sale	0	0
Debt securities held-to-maturity	0	0
Equity securities	348	361
FHLBNY stock, at cost	0	0
Loans held-for-sale	0
Net loans held-for-investment	0	0
Derivative assets	0	0
Financial liabilities:
Deposits	0	0
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	0	0
Subordinated debentures, net of issuance costs	0
Advance payments by borrowers for taxes and insurance	0	0
Derivative liabilities	0	0
Estimated Fair Value | Level 2
Financial assets:
Cash and cash equivalents	0	0
Trading securities	0	0
Debt securities available-for-sale	743,699	952,173
Debt securities held-to-maturity	9,371	10,389
Equity securities	0	0
FHLBNY stock, at cost	41,165	30,382
Loans held-for-sale	0
Net loans held-for-investment	0	0
Derivative assets	6,515	5,321
Financial liabilities:
Deposits	3,669,988	4,148,938
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	850,551	564,588
Subordinated debentures, net of issuance costs	45,196	54,393
Advance payments by borrowers for taxes and insurance	25,968	25,995
Derivative liabilities	6,516	5,321
Estimated Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Trading securities	0	0
Debt securities available-for-sale	0	0
Debt securities held-to-maturity	0	0
Equity securities	0	0
FHLBNY stock, at cost	0	0
Loans held-for-sale	950
Net loans held-for-investment	3,942,539	4,016,849
Derivative assets	0	0
Financial liabilities:
Deposits	0	0
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	0	0
Subordinated debentures, net of issuance costs	0
Advance payments by borrowers for taxes and insurance	0	0
Derivative liabilities	$ 0	$ 0