Securities (Details 2) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	$ 133,120	$ 506,824
Unrealized Losses, Less Than 12 Months	(4,912)	(80,411)
Fair Value, 12 Months or Longer	1,131,064	728,881
Unrealized Losses, 12 Months or Longer	(241,261)	(186,354)
Fair Value, Total	1,264,184	1,235,705
Unrealized Losses, Total	(246,173)	(266,765)
U.S. Treasury and U.S. government sponsored entities
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	14,652	52,311
Unrealized Losses, Less Than 12 Months	(692)	(5,835)
Fair Value, 12 Months or Longer	115,535	75,685
Unrealized Losses, 12 Months or Longer	(19,411)	(15,781)
Fair Value, Total	130,187	127,996
Unrealized Losses, Total	(20,103)	(21,616)
State and political subdivisions
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	73,802	306,709
Unrealized Losses, Less Than 12 Months	(2,835)	(56,650)
Fair Value, 12 Months or Longer	432,373	191,584
Unrealized Losses, 12 Months or Longer	(103,084)	(65,241)
Fair Value, Total	506,175	498,293
Unrealized Losses, Total	(105,919)	(121,891)
Corporate bonds
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	11,011	2,893
Unrealized Losses, Less Than 12 Months	(411)	(122)
Fair Value, 12 Months or Longer	3,561	986
Unrealized Losses, 12 Months or Longer	(311)	(180)
Fair Value, Total	14,572	3,879
Unrealized Losses, Total	(722)	(302)
Mortgage-backed securities - residential
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	4,678	101,476
Unrealized Losses, Less Than 12 Months	(44)	(13,545)
Fair Value, 12 Months or Longer	535,644	453,233
Unrealized Losses, 12 Months or Longer	(112,739)	(104,109)
Fair Value, Total	540,322	554,709
Unrealized Losses, Total	(112,783)	(117,654)
Collateralized mortgage obligations
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	28,977	42,140
Unrealized Losses, Less Than 12 Months	(930)	(4,137)
Fair Value, 12 Months or Longer	40,852	5,214
Unrealized Losses, 12 Months or Longer	(5,356)	(800)
Fair Value, Total	69,829	47,354
Unrealized Losses, Total	(6,286)	(4,937)
Small Business Administration
Investment securities with unrealized losses
Fair Value, Less Than 12 Months	0	1,295
Unrealized Losses, Less Than 12 Months	0	(122)
Fair Value, 12 Months or Longer	3,099	2,179
Unrealized Losses, 12 Months or Longer	(360)	(243)
Fair Value, Total	3,099	3,474
Unrealized Losses, Total	$ (360)	$ (365)

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