Securities, Held to Maturity (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	$ 905,267	$ 919,517
Unrealized gains	271	209
Unrealized losses	(91,014)	(107,079)
Estimated fair value	814,524	812,647
Allowance for credit losses on HTM securities	0	0
Transactions of HTM securities [Abstract]
Gains from calls on HTM securities	0	4	$ 29
Asset Pledged as Collateral [Member] \| Public Deposits and Other Purposes [Member]
Securities pledged [Abstract]
AFS and HTM securities	2,030,000	1,730,000
Asset Pledged as Collateral [Member] \| Securities Sold under Repurchase Agreements [Member]
Securities pledged [Abstract]
AFS and HTM securities	177,200	149,500
Federal Agency [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	100,000	100,000
Unrealized gains	0	0
Unrealized losses	(17,784)	(20,678)
Estimated fair value	82,216	79,322
Mortgage-backed Securities, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	228,720	249,511
Unrealized gains	0	0
Unrealized losses	(31,613)	(36,819)
Estimated fair value	197,107	212,692
Mortgage-Backed, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	17,086	18,396
Unrealized gains	3	4
Unrealized losses	(566)	(619)
Estimated fair value	16,523	17,781
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	187,457	207,738
Unrealized gains	57	200
Unrealized losses	(12,021)	(14,876)
Estimated fair value	175,493	193,062
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	63,878	66,628
Unrealized gains	0	0
Unrealized losses	(10,908)	(9,842)
Estimated fair value	52,970	56,786
State & Municipal [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	308,126	277,244
Unrealized gains	211	5
Unrealized losses	(18,122)	(24,245)
Estimated fair value	$ 290,215	$ 253,004

Gains from calls (requests of early payments) on debt securities which are classified as held-to-maturity securities.

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Amount, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity), and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

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Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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