Available-for-Sale and Held-to-Maturity Securities (Schedule of Gross Unrealized Losses and Estimated Fair Value by Length of Time) (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	$ (1,872)
Available-for-sale Securities, Estimated fair value, Less than 12 months	101,651
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(174,078)
Available-for-sale Securities, Estimated fair value, 12 months or more	1,447,240
Available-for-sale Securities, Gross unrealized losses, Total	(175,950)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,548,891
U.S. Government Agency Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	0
Available-for-sale Securities, Estimated fair value, Less than 12 months	0
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(162)
Available-for-sale Securities, Estimated fair value, 12 months or more	1,775
Available-for-sale Securities, Gross unrealized losses, Total	(162)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,775
Corporate Fixed Income Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(152)
Available-for-sale Securities, Estimated fair value, Less than 12 months	8,297
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(58,818)
Available-for-sale Securities, Estimated fair value, 12 months or more	547,864
Available-for-sale Securities, Gross unrealized losses, Total	(58,970)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	556,161
Mortgage-Backed Securities [Member] \| Agency Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(382)
Available-for-sale Securities, Estimated fair value, Less than 12 months	24,584
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(108,904)
Available-for-sale Securities, Estimated fair value, 12 months or more	721,586
Available-for-sale Securities, Gross unrealized losses, Total	(109,286)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	746,170
Mortgage-Backed Securities [Member] \| Commercial [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	0
Available-for-sale Securities, Estimated fair value, Less than 12 months	0
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(3,655)
Available-for-sale Securities, Estimated fair value, 12 months or more	66,671
Available-for-sale Securities, Gross unrealized losses, Total	(3,655)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	66,671
Mortgage-Backed Securities [Member] \| Non Agency Mortgage Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	0
Available-for-sale Securities, Estimated fair value, Less than 12 months	0
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(13)
Available-for-sale Securities, Estimated fair value, 12 months or more	261
Available-for-sale Securities, Gross unrealized losses, Total	(13)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	261
Asset-Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(1,338)
Available-for-sale Securities, Estimated fair value, Less than 12 months	68,770
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(2,526)
Available-for-sale Securities, Estimated fair value, 12 months or more	109,083
Available-for-sale Securities, Gross unrealized losses, Total	(3,864)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 177,853

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