Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investment securities available-for-sale
Amortized Cost	$ 796,026	$ 849,567
Unrealized Gains	9	21
Unrealized Losses	(156,034)	(132,264)
Fair Value	640,001	717,324
Amortized Cost	303,486	321,902
Unrealized Losses	(55,247)	(50,990)
Allowance for Credit Losses	218
Fair Value	248,239	270,912
Amortized Cost	1,099,512	1,171,469
Unrealized Gains	9	21
Unrealized Losses	(211,281)	(183,254)
Allowance for Credit Losses	218
Fair Value	888,240	988,236
Available-for-Sale accrued interest receivable	2,400	1,900
Held-to-Maturity accrued interest receivable	1,000	1,500
U. S. Treasury and agencies
Investment securities available-for-sale
Amortized Cost	2,679	3,518
Unrealized Gains	9	19
Unrealized Losses	(23)	(17)
Fair Value	2,665	3,520
Mortgage backed securities - Residential agency
Investment securities available-for-sale
Amortized Cost	656,845	705,845
Unrealized Gains		2
Unrealized Losses	(135,222)	(118,168)
Fair Value	521,623	587,679
Amortized Cost	173,398	184,115
Unrealized Losses	(36,596)	(33,254)
Allowance for Credit Losses	103
Fair Value	136,802	150,861
Mortgage backed securities - Commercial
Investment securities available-for-sale
Amortized Cost	66,980	70,669
Unrealized Losses	(8,295)	(7,111)
Fair Value	58,685	63,558
Asset backed securities
Investment securities available-for-sale
Amortized Cost	27	34
Fair Value	27	34
Corporate bonds
Investment securities available-for-sale
Amortized Cost	69,495	69,501
Unrealized Losses	(12,494)	(6,968)
Fair Value	57,001	62,533
Obligations of state and political agencies.
Investment securities available-for-sale
Amortized Cost	130,088	137,787
Unrealized Losses	(18,651)	(17,736)
Allowance for Credit Losses	115
Fair Value	$ 111,437	$ 120,051

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