Investment Securities Schedule of Amortized Cost and Fair Values of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule of Investments [Line Items]
Amortized Cost	$ 3,544,186
Gross Unrealized Gains	19,494
Gross Unrealized Losses	(250,384)
Estimated Fair Value	3,313,296	$ 2,398,352
Amortized Cost, Held to Maturity	1,231,982	1,267,922
Gross Unrealized Gains, Held to Maturity	0	0
Gross Unrealized Losses, Held to Maturity	(167,678)	(195,715)
Debt Securities, Held-to-Maturity, Fair Value	1,064,304	1,072,207
US Government Debt Securities
Schedule of Investments [Line Items]
Amortized Cost		42,475
Gross Unrealized Gains		0
Gross Unrealized Losses		(314)
Estimated Fair Value		42,161
US Government Agencies Debt Securities
Schedule of Investments [Line Items]
Amortized Cost		1,038
Gross Unrealized Gains		0
Gross Unrealized Losses		(28)
Estimated Fair Value		1,010
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	963,138	1,200,571
Gross Unrealized Gains	814	1,089
Gross Unrealized Losses	(112,619)	(129,647)
Estimated Fair Value	851,333	1,072,013
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	318,631	480,714
Gross Unrealized Gains	473	473
Gross Unrealized Losses	(22,524)	(40,636)
Estimated Fair Value	296,580	440,551
Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost	746,328	122,824
Gross Unrealized Gains	11,858	0
Gross Unrealized Losses	(8,718)	(11,390)
Estimated Fair Value	749,468	111,434
Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	911,713	223,273
Gross Unrealized Gains	6,349	7
Gross Unrealized Losses	(22,427)	(26,485)
Estimated Fair Value	895,635	196,795
Amortized Cost, Held to Maturity	373,313	407,075
Gross Unrealized Gains, Held to Maturity	0	0
Gross Unrealized Losses, Held to Maturity	(44,387)	(51,805)
Debt Securities, Held-to-Maturity, Fair Value	328,926	355,270
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	604,376	627,364
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(84,096)	(92,976)
Estimated Fair Value	520,280	534,388
Amortized Cost, Held to Maturity	858,669	860,847
Gross Unrealized Gains, Held to Maturity	0	0
Gross Unrealized Losses, Held to Maturity	(123,291)	(143,910)
Debt Securities, Held-to-Maturity, Fair Value	$ 735,378	716,937
Debt Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost		2,698,259
Gross Unrealized Gains		1,569
Gross Unrealized Losses		(301,476)
Estimated Fair Value		$ 2,398,352