Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Recurring
Assets, Fair Value Disclosure [Abstract]
U.S. Treasury securities		$ 208,204	$ 194,184
U.S. Government agency securities		426,205	396,157
Mortgage-backed securities		1,002,208	971,576
State and municipal securities		1,553,824	1,412,306
Agency-backed securities		172,310	117,403
Corporate notes and other		462,452	467,244
Total investment securities available-for-sale		3,825,203	3,558,870
Other Investments		163,382	153,011
Other assets		189,681	190,629
Total assets at fair value		4,178,266	3,902,510
Liabilities at fair value: [Abstract]
Other liabilities		75,711	96,483
Total liabilities at fair value		75,711	96,483
Recurring | Quoted market prices in an active market (Level 1)
Assets, Fair Value Disclosure [Abstract]
U.S. Treasury securities		0	0
U.S. Government agency securities		0	0
Mortgage-backed securities		0	0
State and municipal securities		0	0
Agency-backed securities		0	0
Corporate notes and other		0	0
Total investment securities available-for-sale		0	0
Other Investments		0	0
Other assets		0	0
Total assets at fair value		0	0
Liabilities at fair value: [Abstract]
Other liabilities		0	0
Total liabilities at fair value		0	0
Recurring | Models with significant observable market parameters (Level 2)
Assets, Fair Value Disclosure [Abstract]
U.S. Treasury securities		208,204	194,184
U.S. Government agency securities		426,205	396,157
Mortgage-backed securities		1,002,208	971,576
State and municipal securities		1,553,345	1,411,677
Agency-backed securities		172,310	117,403
Corporate notes and other		462,452	467,244
Total investment securities available-for-sale		3,824,724	3,558,241
Other Investments		22,372	22,029
Other assets		189,681	190,629
Total assets at fair value		4,036,777	3,770,899
Liabilities at fair value: [Abstract]
Other liabilities		75,711	96,483
Total liabilities at fair value		75,711	96,483
Recurring | Models with significant unobservable market parameters (Level 3)
Assets, Fair Value Disclosure [Abstract]
U.S. Treasury securities		0	0
U.S. Government agency securities		0	0
Mortgage-backed securities		0	0
State and municipal securities		479	629
Agency-backed securities		0	0
Corporate notes and other		0	0
Total investment securities available-for-sale		479	629
Other Investments		141,010	130,982
Other assets		0	0
Total assets at fair value		141,489	131,611
Liabilities at fair value: [Abstract]
Other liabilities		0	0
Total liabilities at fair value		0	0
Nonrecurring
Assets, Fair Value Disclosure [Abstract]
Total assets at fair value		38,703	41,719
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Abstract]
Other real estate owned		7,802	7,952
Collateral dependent loans (1)	[1]	30,901	33,767
Nonrecurring | Quoted market prices in an active market (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total assets at fair value		0	0
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Abstract]
Other real estate owned		0	0
Collateral dependent loans (1)	[1]	0	0
Nonrecurring | Models with significant observable market parameters (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total assets at fair value		0	0
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Abstract]
Other real estate owned		0	0
Collateral dependent loans (1)	[1]	0	0
Nonrecurring | Models with significant unobservable market parameters (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total assets at fair value		38,703	41,719
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Abstract]
Other real estate owned		7,802	7,952
Collateral dependent loans (1)	[1]	$ 30,901	$ 33,767

[1] The carrying values of collateral dependent loans at March 31, 2023 and December 31, 2022 are net of valuation allowances of $7.3 million and $6.5 million, respectively.