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Securities Available for Sale and Held to Maturity - Amortized Cost and Estimated Fair Value of Available for Sale and Held to Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	$ 1,784,943	$ 1,719,537
Securities Available for Sale, Gross Unrealized Gains	45,184	2,988
Securities Available for Sale, Gross Unrealized (Losses)	(15,882)	(29,991)
Securities Available for Sale, Estimated Fair Value	1,814,245	1,692,534
Securities Held to Maturity, Amortized Cost	1,268,459	1,335,385
Securities Held to Maturity, Gross Unrealized Gains	535	98
Securities Held to Maturity, Gross Unrealized (Losses)	(35,258)	(76,376)
Securities Held to Maturity, Estimated Fair Value	1,233,736	1,259,107
U.S. Treasury Securities [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	204,757	203,524
Securities Available for Sale, Gross Unrealized Gains	3,512	548
Securities Available for Sale, Gross Unrealized (Losses)	0	(1,403)
Securities Available for Sale, Estimated Fair Value	208,269	202,669
Securities Held to Maturity, Amortized Cost	30,421	29,842
Securities Held to Maturity, Gross Unrealized Gains	114	1
Securities Held to Maturity, Gross Unrealized (Losses)	0	(522)
Securities Held to Maturity, Estimated Fair Value	30,535	29,321
U.S. Government Agency Obligations [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	70,756	41,194
Securities Available for Sale, Gross Unrealized Gains	575	0
Securities Available for Sale, Gross Unrealized (Losses)	(796)	(2,387)
Securities Available for Sale, Estimated Fair Value	70,535	38,807
Securities Held to Maturity, Amortized Cost	0	0
Securities Held to Maturity, Gross Unrealized Gains	0	0
Securities Held to Maturity, Gross Unrealized (Losses)	0	0
Securities Held to Maturity, Estimated Fair Value	0	0
Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	37,815	31,365
Securities Available for Sale, Gross Unrealized Gains	92	3
Securities Available for Sale, Gross Unrealized (Losses)	(2,101)	(2,957)
Securities Available for Sale, Estimated Fair Value	35,806	28,411
Securities Held to Maturity, Amortized Cost	14,353	16,218
Securities Held to Maturity, Gross Unrealized Gains	5	0
Securities Held to Maturity, Gross Unrealized (Losses)	(445)	(844)
Securities Held to Maturity, Estimated Fair Value	13,913	15,374
Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Available for Sale, Amortized Cost	1,109,332	1,091,122
Securities Available for Sale, Gross Unrealized Gains	30,057	1,610
Securities Available for Sale, Gross Unrealized (Losses)	(12,458)	(22,194)
Securities Available for Sale, Estimated Fair Value	1,126,931	1,070,538
Securities Held to Maturity, Amortized Cost	384,625	423,372
Securities Held to Maturity, Gross Unrealized Gains	345	94
Securities Held to Maturity, Gross Unrealized (Losses)	(9,297)	(23,853)
Securities Held to Maturity, Estimated Fair Value	375,673	399,613
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]
Securities Available for Sale, Amortized Cost	0	0
Securities Available for Sale, Gross Unrealized Gains	0	0
Securities Available for Sale, Gross Unrealized (Losses)	0	0
Securities Available for Sale, Estimated Fair Value	0	0
Securities Held to Maturity, Amortized Cost	103,041	123,685
Securities Held to Maturity, Gross Unrealized Gains	0	0
Securities Held to Maturity, Gross Unrealized (Losses)	(4,794)	(8,004)
Securities Held to Maturity, Estimated Fair Value	98,247	115,681
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]
Securities Available for Sale, Amortized Cost	362,283	352,332
Securities Available for Sale, Gross Unrealized Gains	10,948	827
Securities Available for Sale, Gross Unrealized (Losses)	(527)	(1,050)
Securities Available for Sale, Estimated Fair Value	372,704	352,109
Securities Held to Maturity, Amortized Cost	736,019	742,268
Securities Held to Maturity, Gross Unrealized Gains	71	3
Securities Held to Maturity, Gross Unrealized (Losses)	(20,722)	(43,153)
Securities Held to Maturity, Estimated Fair Value	$ 715,368	$ 699,118

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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