Fair Value Measurements - Estimated Fair Values of the Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financial assets:
Trading securities	$ 14,968	$ 13,884
Debt securities available-for-sale	1,330,904	1,100,817
Debt securities held-to-maturity	8,145	8,762
Financial liabilities:
Subordinated debentures, net of issuance costs	61,610	61,442
Investment measured at fair value	5,000	10,000
Carrying Value
Financial assets:
Cash and cash equivalents	131,725	167,744
Trading securities	14,968	13,884
Debt securities available-for-sale	1,330,904	1,100,817
Debt securities held-to-maturity	8,396	9,303
Equity securities		4,261
FHLBNY stock, at cost	45,718	35,894
Loans held-for-sale		4,897
Net loans held-for-investment	3,863,456	3,987,041
Derivative assets	4,603	5,149
Financial liabilities:
Deposits	3,973,760	4,138,477
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	880,100	666,402
Subordinated debentures, net of issuance costs	61,610	61,442
Advance payments by borrowers for taxes and insurance	23,165	24,057
Derivative liabilities	4,531	5,152
Estimated Fair Value
Financial assets:
Cash and cash equivalents	131,725	167,744
Trading securities	14,968	13,884
Debt securities available-for-sale	1,330,904	1,100,817
Debt securities held-to-maturity	8,145	8,762
Equity securities		4,261
Loans held-for-sale		4,897
Net loans held-for-investment	3,719,487	3,792,302
Derivative assets	4,603	5,149
Financial liabilities:
Deposits	3,974,546	4,139,094
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	879,463	657,705
Subordinated debentures, net of issuance costs	56,085	45,604
Advance payments by borrowers for taxes and insurance	23,165	24,057
Derivative liabilities	4,531	5,152
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	131,725	167,744
Trading securities	14,968	13,884
Debt securities available-for-sale	0	0
Debt securities held-to-maturity	0	0
Equity securities		4,261
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	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	1,330,904	1,100,817
Debt securities held-to-maturity	8,145	8,762
Equity securities		0
Loans held-for-sale		0
Net loans held-for-investment	0	0
Derivative assets	4,603	5,149
Financial liabilities:
Deposits	3,974,546	4,139,094
FHLB advances and other borrowings (including securities sold under agreements to repurchase)	879,463	657,705
Subordinated debentures, net of issuance costs	56,085	45,604
Advance payments by borrowers for taxes and insurance	23,165	24,057
Derivative liabilities	4,531	5,152
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
Loans held-for-sale		4,897
Net loans held-for-investment	3,719,487	3,792,302
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	0
Advance payments by borrowers for taxes and insurance	0	0
Derivative liabilities	$ 0	$ 0