Fair Value of Assets and Liabilities - Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financial Assets
Debt securities, available-for-sale	$ 4,436,578	$ 4,785,719
Recurring Measurements
Financial Assets
Loans held for sale, at fair value	46,126	15,691
Total assets measured at fair value on a recurring basis	4,485,572	4,807,004
Total financial liabilities	20,150	18,338
U.S. government and federal agency
Financial Assets
Debt securities, available-for-sale	467,606	455,347
U.S. government and federal agency | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	467,606	455,347
U.S. government sponsored enterprises
Financial Assets
Debt securities, available-for-sale	310,069	299,219
U.S. government sponsored enterprises | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	310,069	299,219
State and local governments
Financial Assets
Debt securities, available-for-sale	72,370	98,932
State and local governments | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	72,370	98,932
Corporate bonds
Financial Assets
Debt securities, available-for-sale	14,542	26,253
Corporate bonds | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	14,542	26,253
Residential mortgage-backed securities
Financial Assets
Debt securities, available-for-sale	2,524,204	2,811,263
Residential mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	2,524,204	2,811,263
Commercial mortgage-backed securities
Financial Assets
Debt securities, available-for-sale	1,047,787	1,094,705
Commercial mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	1,047,787	1,094,705
Interest rate caps | Recurring Measurements
Financial Assets
Derivative assets	1,883	4,990
Interest rate locks | Recurring Measurements
Financial Assets
Derivative assets	985	604
TBA hedge | Recurring Measurements
Financial Assets
Derivative liabilities	311	350
Interest rate swap | Recurring Measurements
Financial Assets
Derivative liabilities	19,839	17,988
Level 1 | Recurring Measurements
Financial Assets
Loans held for sale, at fair value	0	0
Total assets measured at fair value on a recurring basis	0	0
Total financial liabilities	0	0
Level 1 | U.S. government and federal agency | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | U.S. government sponsored enterprises | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | State and local governments | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Corporate bonds | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Residential mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Commercial mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Interest rate caps | Recurring Measurements
Financial Assets
Derivative assets	0	0
Level 1 | Interest rate locks | Recurring Measurements
Financial Assets
Derivative assets	0	0
Level 1 | TBA hedge | Recurring Measurements
Financial Assets
Derivative liabilities	0	0
Level 1 | Interest rate swap | Recurring Measurements
Financial Assets
Derivative liabilities	0	0
Level 2 | Recurring Measurements
Financial Assets
Loans held for sale, at fair value	46,126	15,691
Total assets measured at fair value on a recurring basis	4,485,572	4,807,004
Total financial liabilities	20,150	18,338
Level 2 | U.S. government and federal agency | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	467,606	455,347
Level 2 | U.S. government sponsored enterprises | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	310,069	299,219
Level 2 | State and local governments | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	72,370	98,932
Level 2 | Corporate bonds | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	14,542	26,253
Level 2 | Residential mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	2,524,204	2,811,263
Level 2 | Commercial mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	1,047,787	1,094,705
Level 2 | Interest rate caps | Recurring Measurements
Financial Assets
Derivative assets	1,883	4,990
Level 2 | Interest rate locks | Recurring Measurements
Financial Assets
Derivative assets	985	604
Level 2 | TBA hedge | Recurring Measurements
Financial Assets
Derivative liabilities	311	350
Level 2 | Interest rate swap | Recurring Measurements
Financial Assets
Derivative liabilities	19,839	17,988
Level 3 | Recurring Measurements
Financial Assets
Loans held for sale, at fair value	0	0
Total assets measured at fair value on a recurring basis	0	0
Total financial liabilities	0	0
Level 3 | U.S. government and federal agency | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | U.S. government sponsored enterprises | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | State and local governments | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Corporate bonds | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Residential mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Commercial mortgage-backed securities | Recurring Measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Interest rate caps | Recurring Measurements
Financial Assets
Derivative assets	0	0
Level 3 | Interest rate locks | Recurring Measurements
Financial Assets
Derivative assets	0	0
Level 3 | TBA hedge | Recurring Measurements
Financial Assets
Derivative liabilities	0	0
Level 3 | Interest rate swap | Recurring Measurements
Financial Assets
Derivative liabilities	$ 0	$ 0