Securities Available for Sale and Held to Maturity - Securities with Gross Unrealized Losses, Segregated by Length of Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$ 349,545	$ 2,078,165
Estimated Fair Value, 12 Months or More	2,758,879	1,342,186
Estimated Fair Value, Total	3,108,424	3,420,351
Gross Unrealized (Losses), Less than 12 Months	(3,485)	(130,121)
Gross Unrealized (Losses), 12 Months or More	(263,507)	(204,848)
Gross Unrealized (Losses), Total	(266,992)	(334,969)
US Treasury Securities [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	29,042	161,298
Estimated Fair Value, 12 Months or More	372,368	258,087
Estimated Fair Value, Total	401,410	419,385
Gross Unrealized (Losses), Less than 12 Months	(26)	(5,655)
Gross Unrealized (Losses), 12 Months or More	(23,811)	(28,974)
Gross Unrealized (Losses), Total	(23,837)	(34,629)
U.S. Government Agency Obligations [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	0	1,828
Estimated Fair Value, 12 Months or More	5,791	5,938
Estimated Fair Value, Total	5,791	7,766
Gross Unrealized (Losses), Less than 12 Months	0	(184)
Gross Unrealized (Losses), 12 Months or More	(416)	(347)
Gross Unrealized (Losses), Total	(416)	(531)
Obligations of States and Political Subdivisions [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months		1,017
Estimated Fair Value, 12 Months or More		3,664
Estimated Fair Value, Total		4,681
Gross Unrealized (Losses), Less than 12 Months		(11)
Gross Unrealized (Losses), 12 Months or More		(3)
Gross Unrealized (Losses), Total		(14)
Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	9,381	27,223
Estimated Fair Value, 12 Months or More	25,967	3,577
Estimated Fair Value, Total	35,348	30,800
Gross Unrealized (Losses), Less than 12 Months	(172)	(3,270)
Gross Unrealized (Losses), 12 Months or More	(2,938)	(569)
Gross Unrealized (Losses), Total	(3,110)	(3,839)
Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	309,466	770,865
Estimated Fair Value, 12 Months or More	1,311,865	1,062,041
Estimated Fair Value, Total	1,621,331	1,832,906
Gross Unrealized (Losses), Less than 12 Months	(3,274)	(41,807)
Gross Unrealized (Losses), 12 Months or More	(176,421)	(173,898)
Gross Unrealized (Losses), Total	(179,695)	(215,705)
Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	0	281,964
Estimated Fair Value, 12 Months or More	230,368	7,235
Estimated Fair Value, Total	230,368	289,199
Gross Unrealized (Losses), Less than 12 Months	0	(21,452)
Gross Unrealized (Losses), 12 Months or More	(16,115)	(989)
Gross Unrealized (Losses), Total	(16,115)	(22,441)
Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,656	833,970
Estimated Fair Value, 12 Months or More	812,520	1,644
Estimated Fair Value, Total	814,176	835,614
Gross Unrealized (Losses), Less than 12 Months	(13)	(57,742)
Gross Unrealized (Losses), 12 Months or More	(43,806)	(68)
Gross Unrealized (Losses), Total	$ (43,819)	$ (57,810)