Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized cost
Due in one year or less	$ 1,895	$ 64,776
Due in one to five years	4,189	75,996
Due in five to ten years	229,469	51,162
Due in over ten years	452,085	391,270
Amortized cost, sub-total	687,638	583,204
Amortized cost, AFS debt securities	1,673,079	1,658,779
Fair Value
Due in one year or less	1,892	64,279
Due in one to five years	4,143	71,801
Due in five to ten years	228,476	49,630
Due in over ten years	437,533	372,331
Fair value, sub-total	672,044	558,041
Total AFS debt securities	1,567,922	1,471,973
Mortgage-backed securities - residential
Amortized cost
Mortgage-backed securities	968,294	1,057,389
Amortized cost, AFS debt securities	968,294	1,057,389
Fair Value
Mortgage-backed securities	879,589	896,971
Total AFS debt securities	879,589	896,971
Mortgage-backed securities - commercial
Amortized cost
Mortgage-backed securities	17,147	18,186
Amortized cost, AFS debt securities	17,147	18,186
Fair Value
Mortgage-backed securities	16,289	16,961
Total AFS debt securities	$ 16,289	$ 16,961