Securities - Schedule of Securities with Unrealized Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	$ 82,479	$ 1,018,313
Less than 12 Months, Unrealized Loss	(2,003)	(177,161)
12 Months or More, Fair Value	1,475,399	603,633
12 Months or More, Unrealized Loss	(313,177)	(156,691)
Total Fair Value	1,557,878	1,621,946
Total Unrealized Loss	(315,180)	(333,852)
U.S. Treasury
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Loss	0	0
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Loss	0	0
Total Fair Value	0	0
Total Unrealized Loss	0	0
Obligations of State and Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	59,277	579,267
Less than 12 Months, Unrealized Loss	(688)	(117,423)
12 Months or More, Fair Value	646,205	122,992
12 Months or More, Unrealized Loss	(146,757)	(44,591)
Total Fair Value	705,482	702,259
Total Unrealized Loss	(147,445)	(162,014)
MBS/CMO
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	23,202	240,344
Less than 12 Months, Unrealized Loss	(1,315)	(20,920)
12 Months or More, Fair Value	642,660	474,327
12 Months or More, Unrealized Loss	(126,731)	(110,918)
Total Fair Value	665,862	714,671
Total Unrealized Loss	(128,046)	(131,838)
US Gov’t Sponsored Entities & Agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	198,702
Less than 12 Months, Unrealized Loss	0	(38,818)
12 Months or More, Fair Value	186,534	6,314
12 Months or More, Unrealized Loss	(39,689)	(1,182)
Total Fair Value	186,534	205,016
Total Unrealized Loss	$ (39,689)	$ (40,000)