Securities - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	$ 68,345	$ 55,991
Available for Sale, Unrealized Losses, Less than 12 Months	(332)	(420)
Available for Sale, Estimated Fair Value, 12 Months or More	233,628	215,455
Available for Sale, Unrealized Losses, 12 Months or More	(3,396)	(3,793)
Available for Sale, Estimated Fair Value, Total	301,973	271,446
Available for Sale, Unrealized Losses, Total	(3,728)	(4,213)
Held to Maturity, Estimated Fair Value, Less than 12 Months	169,661	388,714
Held to Maturity, Unrealized Losses, Less than 12 Months	(1,759)	(5,467)
Held to Maturity, Estimated Fair Value, 12 Months or More	8,738,887	8,882,499
Held to Maturity, Unrealized Losses, 12 Months or More	(1,156,113)	(1,370,118)
Held to Maturity, Estimated Fair Value, Total	8,908,548	9,271,213
Held to Maturity, Unrealized Losses, Total	(1,157,872)	(1,375,585)
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months		2,040
Available for Sale, Unrealized Losses, Less than 12 Months		(60)
Available for Sale, Estimated Fair Value, Total		2,040
Available for Sale, Unrealized Losses, Total		(60)
Held to Maturity, Estimated Fair Value, 12 Months or More	8,640	8,160
Held to Maturity, Unrealized Losses, 12 Months or More	(3,360)	(3,840)
Held to Maturity, Estimated Fair Value, Total	8,640	8,160
Held to Maturity, Unrealized Losses, Total	(3,360)	(3,840)
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	53,344	47,114
Available for Sale, Unrealized Losses, Less than 12 Months	(244)	(307)
Available for Sale, Estimated Fair Value, 12 Months or More	144,740	125,942
Available for Sale, Unrealized Losses, 12 Months or More	(2,572)	(2,926)
Available for Sale, Estimated Fair Value, Total	198,084	173,056
Available for Sale, Unrealized Losses, Total	(2,816)	(3,233)
Held to Maturity, Estimated Fair Value, Less than 12 Months	27,629	28,362
Held to Maturity, Unrealized Losses, Less than 12 Months	(93)	(663)
Held to Maturity, Estimated Fair Value, 12 Months or More	180,046	179,855
Held to Maturity, Unrealized Losses, 12 Months or More	(16,805)	(23,465)
Held to Maturity, Estimated Fair Value, Total	207,675	208,217
Held to Maturity, Unrealized Losses, Total	(16,898)	(24,128)
Mortgage-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	15,001	6,837
Available for Sale, Unrealized Losses, Less than 12 Months	(88)	(53)
Available for Sale, Estimated Fair Value, 12 Months or More	88,888	89,513
Available for Sale, Unrealized Losses, 12 Months or More	(824)	(867)
Available for Sale, Estimated Fair Value, Total	103,889	96,350
Available for Sale, Unrealized Losses, Total	(912)	(920)
Held to Maturity, Estimated Fair Value, Less than 12 Months	121,645	331,265
Held to Maturity, Unrealized Losses, Less than 12 Months	(1,552)	(4,647)
Held to Maturity, Estimated Fair Value, 12 Months or More	8,515,283	8,646,541
Held to Maturity, Unrealized Losses, 12 Months or More	(1,133,778)	(1,340,416)
Held to Maturity, Estimated Fair Value, Total	8,636,928	8,977,806
Held to Maturity, Unrealized Losses, Total	(1,135,330)	(1,345,063)
U.S. Government Agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	5,881	5,817
Held to Maturity, Unrealized Losses, Less than 12 Months	(22)	(44)
Held to Maturity, Estimated Fair Value, Total	5,881	5,817
Held to Maturity, Unrealized Losses, Total	(22)	(44)
States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	14,506	23,270
Held to Maturity, Unrealized Losses, Less than 12 Months	(92)	(113)
Held to Maturity, Estimated Fair Value, 12 Months or More	34,918	47,943
Held to Maturity, Unrealized Losses, 12 Months or More	(2,170)	(2,397)
Held to Maturity, Estimated Fair Value, Total	49,424	71,213
Held to Maturity, Unrealized Losses, Total	$ (2,262)	$ (2,510)

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