Assets and Liabilities Measured at Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Debt securities available-for-sale	$ 3,393,399	$ 3,331,084
Mortgage loans held for sale	38,140	33,008
U.S. Treasuries
Assets:
Debt securities available-for-sale	398,780	387,349
U.S. Government agencies & GSEs
Assets:
Debt securities available-for-sale	297,426	267,500
State and political subdivisions
Assets:
Debt securities available-for-sale	163,263	164,049
Corporate bonds
Assets:
Debt securities available-for-sale	195,900	201,222
Asset-backed securities
Assets:
Debt securities available-for-sale	147,056	161,712
Recurring
Assets:
Equity securities with readily determinable fair values	6,340	7,395
Mortgage loans held for sale	38,140	33,008
Deferred compensation plan assets	13,124	12,791
Servicing rights for SBA/USDA loans	5,507	5,444
Residential mortgage servicing rights	37,358	35,897
Derivative financial instruments	53,202	50,352
Total assets	3,547,070	3,475,971
Liabilities:
Deferred compensation plan liability	13,119	12,838
Derivative financial instruments	91,413	84,811
Total liabilities	104,532	97,649
Recurring | U.S. Treasuries
Assets:
Debt securities available-for-sale	398,780	387,349
Recurring | U.S. Government agencies & GSEs
Assets:
Debt securities available-for-sale	297,426	267,500
Recurring | State and political subdivisions
Assets:
Debt securities available-for-sale	163,263	164,049
Recurring | Residential MBS
Assets:
Debt securities available-for-sale	1,517,893	1,507,598
Recurring | Commercial MBS
Assets:
Debt securities available-for-sale	673,081	641,654
Recurring | Corporate bonds
Assets:
Debt securities available-for-sale	195,900	201,222
Recurring | Asset-backed securities
Assets:
Debt securities available-for-sale	147,056	161,712
Recurring | Level 1
Assets:
Equity securities with readily determinable fair values	4,553	5,767
Mortgage loans held for sale	0	0
Deferred compensation plan assets	13,124	12,791
Servicing rights for SBA/USDA loans	0	0
Residential mortgage servicing rights	0	0
Derivative financial instruments	0	0
Total assets	416,457	405,907
Liabilities:
Deferred compensation plan liability	13,119	12,838
Derivative financial instruments	0	0
Total liabilities	13,119	12,838
Recurring | Level 1 | U.S. Treasuries
Assets:
Debt securities available-for-sale	398,780	387,349
Recurring | Level 1 | U.S. Government agencies & GSEs
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 1 | State and political subdivisions
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 1 | Residential MBS
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 1 | Commercial MBS
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 1 | Corporate bonds
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 1 | Asset-backed securities
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 2
Assets:
Equity securities with readily determinable fair values	1,787	1,628
Mortgage loans held for sale	38,140	33,008
Deferred compensation plan assets	0	0
Servicing rights for SBA/USDA loans	0	0
Residential mortgage servicing rights	0	0
Derivative financial instruments	40,391	39,710
Total assets	3,072,777	3,015,876
Liabilities:
Deferred compensation plan liability	0	0
Derivative financial instruments	78,228	73,639
Total liabilities	78,228	73,639
Recurring | Level 2 | U.S. Treasuries
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 2 | U.S. Government agencies & GSEs
Assets:
Debt securities available-for-sale	297,426	267,500
Recurring | Level 2 | State and political subdivisions
Assets:
Debt securities available-for-sale	163,263	164,049
Recurring | Level 2 | Residential MBS
Assets:
Debt securities available-for-sale	1,517,893	1,507,598
Recurring | Level 2 | Commercial MBS
Assets:
Debt securities available-for-sale	673,081	641,654
Recurring | Level 2 | Corporate bonds
Assets:
Debt securities available-for-sale	193,740	199,017
Recurring | Level 2 | Asset-backed securities
Assets:
Debt securities available-for-sale	147,056	161,712
Recurring | Level 3
Assets:
Equity securities with readily determinable fair values	0	0
Mortgage loans held for sale	0	0
Deferred compensation plan assets	0	0
Servicing rights for SBA/USDA loans	5,507	5,444
Residential mortgage servicing rights	37,358	35,897
Derivative financial instruments	12,811	10,642
Total assets	57,836	54,188
Liabilities:
Deferred compensation plan liability	0	0
Derivative financial instruments	13,185	11,172
Total liabilities	13,185	11,172
Recurring | Level 3 | U.S. Treasuries
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 3 | U.S. Government agencies & GSEs
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 3 | State and political subdivisions
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 3 | Residential MBS
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 3 | Commercial MBS
Assets:
Debt securities available-for-sale	0	0
Recurring | Level 3 | Corporate bonds
Assets:
Debt securities available-for-sale	2,160	2,205
Recurring | Level 3 | Asset-backed securities
Assets:
Debt securities available-for-sale	$ 0	$ 0