Securities, Held to Maturity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	$ 906,824		$ 919,517
Unrealized gains	424		209
Unrealized losses	(94,584)		(107,079)
Estimated fair value	812,664		812,647
Allowance for credit losses on HTM securities	0		0
Transactions of HTM securities [Abstract]
Gains from calls on HTM securities	0	$ 4
Asset Pledged as Collateral [Member] \| Public Deposits or Other Purposes [Member]
Securities pledged [Abstract]
AFS and HTM securities	1,760,000		1,730,000
Asset Pledged as Collateral [Member] \| Securities Sold under Repurchase Agreements [Member]
Securities pledged [Abstract]
AFS and HTM securities	142,200		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	(19,055)		(20,678)
Estimated fair value	80,945		79,322
Mortgage-Backed, Government Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	244,670		249,511
Unrealized gains	0		0
Unrealized losses	(33,729)		(36,819)
Estimated fair value	210,941		212,692
Mortgage-Backed, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	17,399		18,396
Unrealized gains	3		4
Unrealized losses	(464)		(619)
Estimated fair value	16,938		17,781
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	202,831		207,738
Unrealized gains	274		200
Unrealized losses	(12,236)		(14,876)
Estimated fair value	190,869		193,062
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	65,989		66,628
Unrealized gains	0		0
Unrealized losses	(9,651)		(9,842)
Estimated fair value	56,338		56,786
State & Municipal [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	275,935		277,244
Unrealized gains	147		5
Unrealized losses	(19,449)		(24,245)
Estimated fair value	$ 256,633		$ 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).

+ References

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

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-Publisher FASB
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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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