Investment Securities, AFS and HTM Securities Amortized Costs and Fair Values (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	$ 5,193,828	$ 4,605,954
Debt Securities, Available-for-Sale	5,217,278	4,581,434
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(12,346)	(30,213)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	35,796	5,693
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,636,139	3,738,747
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	37,331	42,653
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(491,077)	(595,906)
Debt Securities, Held-to-Maturity, Fair Value	3,182,394	3,185,494
US Treasury Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	995	1,000
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	19	0
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	0	(1)
Debt Securities, Held-to-Maturity, Fair Value	1,014	999
US Treasury Securities | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	995	1,000
Debt Securities, Held-to-Maturity, Fair Value	1,014	999
US Treasury Securities | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Fair Value	0	0
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, Amortized Cost	3,063	3,063
Debt Securities, Available-for-Sale	3,019	3,005
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(45)	(58)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	1	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,637,318	1,659,722
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	1,640	1,122
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(153,562)	(174,202)
Debt Securities, Held-to-Maturity, Fair Value	1,485,396	1,486,642
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	3,019	3,005
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,637,318	1,659,662
Debt Securities, Held-to-Maturity, Fair Value	1,485,396	1,486,582
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	3,019	3,005
Debt Securities, Held-to-Maturity, Fair Value	1,485,396	1,486,582
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	0
Debt Securities, Available-for-Sale	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	307,569	324,182
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	7,019	8,135
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(53,549)	(65,963)
Debt Securities, Held-to-Maturity, Fair Value	261,038	266,353
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, Amortized Cost	98,889	108,319
Debt Securities, Available-for-Sale	98,198	107,839
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(731)	(604)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	39	123
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	98,198	107,839
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	98,198	107,839
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	363	495
Debt Securities, Available-for-Sale	348	471
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(15)	(24)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	348	471
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	348	471
Other Debt securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	3,000	3,000
Debt Securities, Available-for-Sale	3,000	2,989
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	0	(11)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	128,541	120,272
Debt Securities, Available-for-Sale	123,560	110,928
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(5,888)	(9,534)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	907	190
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	836,619	885,476
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	19,924	22,934
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(150,818)	(186,464)
Debt Securities, Held-to-Maturity, Fair Value	705,725	721,946
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	123,560	110,928
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	836,619	885,476
Debt Securities, Held-to-Maturity, Fair Value	705,725	721,946
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	123,560	110,928
Debt Securities, Held-to-Maturity, Fair Value	705,725	721,946
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	18,054	18,332
Debt Securities, Available-for-Sale	16,999	17,000
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(1,055)	(1,332)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	766,482	772,456
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	8,503	10,217
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(125,634)	(159,078)
Debt Securities, Held-to-Maturity, Fair Value	649,352	623,595
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	16,999	17,000
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	766,482	772,456
Debt Securities, Held-to-Maturity, Fair Value	649,352	623,595
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	16,999	17,000
Debt Securities, Held-to-Maturity, Fair Value	649,352	623,595
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	4,827,672	4,236,199
Debt Securities, Available-for-Sale	4,862,225	4,227,727
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(295)	(13,851)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	34,848	5,379
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	40,301	43,693
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	60	9
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(2,490)	(3,774)
Debt Securities, Held-to-Maturity, Fair Value	37,871	39,927
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	4,862,225	4,227,727
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	40,301	43,693
Debt Securities, Held-to-Maturity, Fair Value	37,871	39,927
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	4,862,225	4,227,727
Debt Securities, Held-to-Maturity, Fair Value	37,871	39,927
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	114,247	116,275
Debt Securities, Available-for-Sale	109,930	111,475
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(4,317)	(4,800)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	46,855	52,219
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	166	236
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(5,023)	(6,424)
Debt Securities, Held-to-Maturity, Fair Value	41,998	46,032
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	109,930	111,475
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	46,855	52,219
Debt Securities, Held-to-Maturity, Fair Value	41,998	46,032
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	109,930	111,475
Debt Securities, Held-to-Maturity, Fair Value	$ 41,998	$ 46,032