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Securities, Held to Maturity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	$ 733,210	$ 616,560
Unrealized gains	10,040	21,942
Unrealized losses	7,990	1,675
Estimated fair value	735,260	636,827
Allowance for credit losses on HTM securities	0	0
Transactions of HTM securities [Abstract]
Gains from calls on HTM securities	29	24	$ 12
Held-to-maturity securities sold, amortized cost	0	1,000	$ 0
Held-to-maturity securities sold, realized loss		1
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	4,365	1,658
Estimated fair value	95,635	98,342
Mortgage-backed Securities, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	161,462	107,914
Unrealized gains	2,232	4,583
Unrealized losses	1,319	0
Estimated fair value	162,375	112,497
Mortgage-Backed, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	9,112	11,533
Unrealized gains	514	979
Unrealized losses	0	0
Estimated fair value	9,626	12,512
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	94,342	103,105
Unrealized gains	1,932	4,477
Unrealized losses	129	0
Estimated fair value	96,145	107,582
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	44,473	79,145
Unrealized gains	336	3,950
Unrealized losses	674	0
Estimated fair value	44,135	83,095
State & Municipal [Member]
Held-to-maturity securities, fair value to amortized cost [Abstract]
Amortized cost	323,821	214,863
Unrealized gains	5,026	7,953
Unrealized losses	1,503	17
Estimated fair value	327,344	222,799
Public Deposits and Other Purposes [Member]
Securities pledged [Abstract]
Amortized costs of securities available for sale and held to maturity pledged	1,600,000	1,400,000
Securities Sold under Repurchase Agreements [Member]
Securities pledged [Abstract]
Amortized costs of securities available for sale and held to maturity pledged	$ 162,100	$ 305,200

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Amount of realized loss on investment in debt security measured at amortized cost (held-to-maturity), which was sold during the period.

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