Securities - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	$ 81,563	$ 61,828
Available for Sale, Unrealized Losses, Less than 12 Months	(433)	(162)
Available for Sale, Estimated Fair Value, 12 Months or More	215,966	241,350
Available for Sale, Unrealized Losses, 12 Months or More	(2,490)	(2,821)
Available for Sale, Estimated Fair Value, Total	297,529	303,178
Available for Sale, Unrealized Losses, Total	(2,923)	(2,983)
Held to Maturity, Estimated Fair Value, Less than 12 Months	2,349,846	396,884
Held to Maturity, Unrealized Losses, Less than 12 Months	(21,469)	(854)
Held to Maturity, Estimated Fair Value, 12 Months or More	7,611,613	8,013,220
Held to Maturity, Unrealized Losses, 12 Months or More	(892,095)	(851,416)
Held to Maturity, Estimated Fair Value, Total	9,961,459	8,410,104
Held to Maturity, Unrealized Losses, Total	(913,564)	(852,270)
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, 12 Months or More	11,100	10,980
Held to Maturity, Unrealized Losses, 12 Months or More	(900)	(1,020)
Held to Maturity, Estimated Fair Value, Total	11,100	10,980
Held to Maturity, Unrealized Losses, Total	(900)	(1,020)
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	10,917	29,345
Available for Sale, Unrealized Losses, Less than 12 Months	(56)	(71)
Available for Sale, Estimated Fair Value, 12 Months or More	165,071	159,382
Available for Sale, Unrealized Losses, 12 Months or More	(2,188)	(2,179)
Available for Sale, Estimated Fair Value, Total	175,988	188,727
Available for Sale, Unrealized Losses, Total	(2,244)	(2,250)
Held to Maturity, Estimated Fair Value, Less than 12 Months	162,914	548
Held to Maturity, Unrealized Losses, Less than 12 Months	(2,233)	(8)
Held to Maturity, Estimated Fair Value, 12 Months or More	156,204	165,061
Held to Maturity, Unrealized Losses, 12 Months or More	(13,272)	(12,169)
Held to Maturity, Estimated Fair Value, Total	319,118	165,609
Held to Maturity, Unrealized Losses, Total	(15,505)	(12,177)
Mortgage-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	70,646	32,483
Available for Sale, Unrealized Losses, Less than 12 Months	(377)	(91)
Available for Sale, Estimated Fair Value, 12 Months or More	50,895	81,968
Available for Sale, Unrealized Losses, 12 Months or More	(302)	(642)
Available for Sale, Estimated Fair Value, Total	121,541	114,451
Available for Sale, Unrealized Losses, Total	(679)	(733)
Held to Maturity, Estimated Fair Value, Less than 12 Months	2,139,258	390,495
Held to Maturity, Unrealized Losses, Less than 12 Months	(18,674)	(775)
Held to Maturity, Estimated Fair Value, 12 Months or More	7,421,363	7,813,697
Held to Maturity, Unrealized Losses, 12 Months or More	(876,503)	(836,881)
Held to Maturity, Estimated Fair Value, Total	9,560,621	8,204,192
Held to Maturity, Unrealized Losses, Total	(895,177)	(837,656)
U.S. Government agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	4,068	4,733
Held to Maturity, Unrealized Losses, Less than 12 Months	(5)	(70)
Held to Maturity, Estimated Fair Value, 12 Months or More	0
Held to Maturity, Unrealized Losses, 12 Months or More	0
Held to Maturity, Estimated Fair Value, Total	4,068	4,733
Held to Maturity, Unrealized Losses, Total	(5)	(70)
States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	43,606	1,108
Held to Maturity, Unrealized Losses, Less than 12 Months	(557)	(1)
Held to Maturity, Estimated Fair Value, 12 Months or More	22,946	23,482
Held to Maturity, Unrealized Losses, 12 Months or More	(1,420)	(1,346)
Held to Maturity, Estimated Fair Value, Total	66,552	24,590
Held to Maturity, Unrealized Losses, Total	$ (1,977)	$ (1,347)

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