Investment Securities, AFS and HTM Securities Gross Unrealized Losses (Details) $ in Thousands	Sep. 30, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	336	446
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (40,967)	$ (48,263)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 1,506,947	$ 847,391
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	371	121
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (283,760)	$ (207,575)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,903,609	1,576,665
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(324,727)	(255,837)
Debt Securities, Available-for-sale, Unrealized Loss Position	3,410,556	2,424,055
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	(54,112)	(134,556)
Fair value of unrealized losses on held to maturity securities, less than 12 months	736,544	1,381,511
Unrealized losses on held to maturity securities, 12 months or more	(752,515)	(485,855)
Fair value of unrealized losses on held to maturity securities, 12 months or more	2,395,440	1,752,354
Total unrealized losses on held to maturity securities	(806,627)	(620,411)
Total fair value of unrealized losses on held to maturity securities	$ 3,131,984	$ 3,133,865
US Treasury Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	7	7
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (15,531)	$ (15,063)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	109,024	109,378
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(15,531)	(15,063)
Debt Securities, Available-for-sale, Unrealized Loss Position	109,024	109,378
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	0	(62)
Fair value of unrealized losses on held to maturity securities, less than 12 months	0	936
Unrealized losses on held to maturity securities, 12 months or more	(51)	0
Fair value of unrealized losses on held to maturity securities, 12 months or more	948	0
Total unrealized losses on held to maturity securities	(51)	(62)
Total fair value of unrealized losses on held to maturity securities	$ 948	$ 936
Agency Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	1	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (1,410)	$ (1,468)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	13,590	13,532
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,410)	(1,468)
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 13,590	$ 13,532
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	229	358
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (6,575)	$ (5,066)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 108,953	$ 201,260
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	182	4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (9,916)	$ (8)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	100,413	1,916
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(16,492)	(5,074)
Debt Securities, Available-for-sale, Unrealized Loss Position	209,367	203,176
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	(48,660)	(96,282)
Fair value of unrealized losses on held to maturity securities, less than 12 months	663,360	1,079,216
Unrealized losses on held to maturity securities, 12 months or more	(230,998)	(86,415)
Fair value of unrealized losses on held to maturity securities, 12 months or more	743,274	231,022
Total unrealized losses on held to maturity securities	(279,659)	(182,697)
Total fair value of unrealized losses on held to maturity securities	1,406,634	1,310,238
Mortgage-backed Securities, Issued by Private Enterprises [Member]
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	0	(9,509)
Fair value of unrealized losses on held to maturity securities, less than 12 months	0	58,733
Unrealized losses on held to maturity securities, 12 months or more	(85,120)	(63,411)
Fair value of unrealized losses on held to maturity securities, 12 months or more	274,518	244,772
Total unrealized losses on held to maturity securities	(85,120)	(72,920)
Total fair value of unrealized losses on held to maturity securities	$ 274,518	$ 303,505
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	0	3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ (1,668)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 44,304
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	14	12
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (2,450)	$ (4,278)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	129,503	106,887
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,450)	(5,947)
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 129,503	$ 151,191
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	2	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (1)	$ (1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 620	$ 417
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	7	6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (46)	$ (50)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,525	2,057
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(46)	(51)
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 2,144	$ 2,474
Other Debt securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	1	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (21)	$ (30)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 979	$ 1,970
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	2	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (63)	$ (49)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,937	951
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(85)	(78)
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 2,915	$ 2,922
FNMA/FHLMC | Residential Related Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	20	24
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (1,390)	$ (31,266)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 24,258	$ 260,986
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	107	84
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (240,606)	$ (185,170)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,394,562	1,321,420
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(241,997)	(216,436)
Debt Securities, Available-for-sale, Unrealized Loss Position	1,418,820	1,582,406
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	(2,239)	(18,925)
Fair value of unrealized losses on held to maturity securities, less than 12 months	37,996	143,201
Unrealized losses on held to maturity securities, 12 months or more	(218,338)	(156,836)
Fair value of unrealized losses on held to maturity securities, 12 months or more	725,539	671,570
Total unrealized losses on held to maturity securities	(220,577)	(175,760)
Total fair value of unrealized losses on held to maturity securities	$ 763,535	$ 814,770
FNMA/FHLMC | Commercial mortgage-related securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	0	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ (1,896)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 17,142
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	1	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (2,625)	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	16,154	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,625)	(1,896)
Debt Securities, Available-for-sale, Unrealized Loss Position	16,154	17,142
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	(2,746)	(3,814)
Fair value of unrealized losses on held to maturity securities, less than 12 months	24,130	20,338
Unrealized losses on held to maturity securities, 12 months or more	(203,776)	(174,467)
Fair value of unrealized losses on held to maturity securities, 12 months or more	564,968	576,911
Total unrealized losses on held to maturity securities	(206,522)	(178,281)
Total fair value of unrealized losses on held to maturity securities	$ 589,097	$ 597,249
Government National Mortgage Association (GNMA) [Member] | Residential Related Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	75	23
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (27,131)	$ (4,415)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 1,271,478	$ 220,276
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	17	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (4,767)	$ (840)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	61,087	11,096
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(31,898)	(5,255)
Debt Securities, Available-for-sale, Unrealized Loss Position	1,332,565	231,372
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	(466)	(3,436)
Fair value of unrealized losses on held to maturity securities, less than 12 months	11,058	44,476
Unrealized losses on held to maturity securities, 12 months or more	(4,726)	0
Fair value of unrealized losses on held to maturity securities, 12 months or more	34,253	0
Total unrealized losses on held to maturity securities	(5,192)	(3,436)
Total fair value of unrealized losses on held to maturity securities	$ 45,312	$ 44,476
Government National Mortgage Association (GNMA) [Member] | Commercial mortgage-related securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | security	9	33
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (5,848)	$ (3,920)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 100,659	$ 101,036
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | security	33	4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (6,345)	$ (649)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	75,815	9,426
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(12,193)	(4,569)
Debt Securities, Available-for-sale, Unrealized Loss Position	176,474	110,462
HTM investment securities
Unrealized losses on held to maturity securities, less than 12 months	0	(2,528)
Fair value of unrealized losses on held to maturity securities, less than 12 months	0	34,612
Unrealized losses on held to maturity securities, 12 months or more	(9,506)	(4,726)
Fair value of unrealized losses on held to maturity securities, 12 months or more	51,940	28,080
Total unrealized losses on held to maturity securities	(9,506)	(7,254)
Total fair value of unrealized losses on held to maturity securities	$ 51,940	$ 62,691
Held to maturity, number of securities, less than 12 months
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	627	947
Held to maturity, number of securities, less than 12 months | US Treasury Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	0	1
Held to maturity, number of securities, less than 12 months | US States and Political Subdivisions Debt Securities [Member]
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	586	771
Held to maturity, number of securities, less than 12 months | Mortgage-backed Securities, Issued by Private Enterprises [Member]
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	0	3
Held to maturity, number of securities, less than 12 months | FNMA/FHLMC | Residential Related Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	31	79
Held to maturity, number of securities, less than 12 months | FNMA/FHLMC | Commercial mortgage-related securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	2	4
Held to maturity, number of securities, less than 12 months | Government National Mortgage Association (GNMA) [Member] | Residential Related Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	8	81
Held to maturity, number of securities, less than 12 months | Government National Mortgage Association (GNMA) [Member] | Commercial mortgage-related securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	0	8
Held to maturity, number of securities, 12 months or more
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	812	238
Held to maturity, number of securities, 12 months or more | US Treasury Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	1	0
Held to maturity, number of securities, 12 months or more | US States and Political Subdivisions Debt Securities [Member]
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	567	156
Held to maturity, number of securities, 12 months or more | Mortgage-backed Securities, Issued by Private Enterprises [Member]
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	18	15
Held to maturity, number of securities, 12 months or more | FNMA/FHLMC | Residential Related Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	92	22
Held to maturity, number of securities, 12 months or more | FNMA/FHLMC | Commercial mortgage-related securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	43	39
Held to maturity, number of securities, 12 months or more | Government National Mortgage Association (GNMA) [Member] | Residential Related Securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	78	0
Held to maturity, number of securities, 12 months or more | Government National Mortgage Association (GNMA) [Member] | Commercial mortgage-related securities
HTM investment securities
Number of held to maturity securities in a continuous unrealized loss position | security	13	6