Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Investment securities available-for-sale
Amortized Cost	$ 923,667	$ 860,258
Unrealized Gains	1,006	5,362
Unrealized Losses	(58,340)	(11,971)
Fair Value	866,333	853,649
Amortized Cost	340,150	352,061
Unrealized Gains	1	1,110
Unrealized Losses	(22,325)	(3,494)
Fair Value	317,826	349,677
Amortized Cost	1,263,817	1,212,319
Unrealized Gains	1,007	6,472
Unrealized Losses	(80,665)	(15,465)
Fair Value	1,184,159	1,203,326
U. S. Treasury and agencies
Investment securities available-for-sale
Amortized Cost	4,107	5,028
Unrealized Gains	60	75
Fair Value	4,167	5,103
Obligations of state and political agencies.
Investment securities available-for-sale
Amortized Cost	141,373	144,543
Unrealized Gains	1	1,110
Unrealized Losses	(7,594)	(349)
Fair Value	133,780	145,304
Mortgage backed securities - Residential agency
Investment securities available-for-sale
Amortized Cost	765,363	717,781
Unrealized Gains	229	1,213
Unrealized Losses	(54,471)	(11,837)
Fair Value	711,121	707,157
Amortized Cost	198,777	207,518
Unrealized Losses	(14,731)	(3,145)
Fair Value	184,046	204,373
Mortgage backed securities - Commercial
Investment securities available-for-sale
Amortized Cost	85,123	88,362
Unrealized Gains	185	2,674
Unrealized Losses	(2,576)	(123)
Fair Value	82,732	90,913
Asset backed securities
Investment securities available-for-sale
Amortized Cost	41	52
Unrealized Gains	1	2
Fair Value	42	54
Corporate bonds
Investment securities available-for-sale
Amortized Cost	69,033	49,035
Unrealized Gains	531	1,398
Unrealized Losses	(1,293)	(11)
Fair Value	$ 68,271	$ 50,422

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