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Securities - Continuous Unrealized Losses (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
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Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | $ 1,600,117 | $ 125,924
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | (4,571) | (721)
Available-for-sale debt securities, 12 Months or More, Fair Value | 4,900,507 | 5,532,528
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (731,907) | (728,216)
Available-for-sale debt securities fair value, Total | 6,500,624 | 5,658,452
Available-for-sale debt securities, Gross Unrealized Loss, Total | (736,478) | (728,937)
U.S. Treasury securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 621,094 | 623,978
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (55,196) | (52,313)
Available-for-sale debt securities fair value, Total | 621,094 | 623,978
Available-for-sale debt securities, Gross Unrealized Loss, Total | (55,196) | (52,313)
U.S. government agency and U.S. government-sponsored enterprise debt securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 360,802 | 364,446
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (49,874) | (47,640)
Available-for-sale debt securities fair value, Total | 360,802 | 364,446
Available-for-sale debt securities, Gross Unrealized Loss, Total | (49,874) | (47,640)
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 450,965 | 463,572
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (57,669) | (63,276)
Available-for-sale debt securities fair value, Total | 450,965 | 463,572
Available-for-sale debt securities, Gross Unrealized Loss, Total | (57,669) | (63,276)
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 1,577,361 | 9,402
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | (4,504) | (558)
Available-for-sale debt securities, 12 Months or More, Fair Value | 1,642,455 | 1,661,112
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (236,858) | (229,155)
Available-for-sale debt securities fair value, Total | 3,219,816 | 1,670,514
Available-for-sale debt securities, Gross Unrealized Loss, Total | (241,362) | (229,713)
Municipal securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 4,189 | 2,825
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | (6) | (15)
Available-for-sale debt securities, 12 Months or More, Fair Value | 252,268 | 254,773
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (37,906) | (36,327)
Available-for-sale debt securities fair value, Total | 256,457 | 257,598
Available-for-sale debt securities, Gross Unrealized Loss, Total | (37,912) | (36,342)
Non-agency commercial mortgage-backed securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 2,742
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | (4)
Available-for-sale debt securities, 12 Months or More, Fair Value | 333,996 | 364,774
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (39,838) | (42,058)
Available-for-sale debt securities fair value, Total | 333,996 | 367,516
Available-for-sale debt securities, Gross Unrealized Loss, Total | (39,838) | (42,062)
Non-agency residential mortgage-backed securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 519,657 | 553,671
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (90,048) | (89,664)
Available-for-sale debt securities fair value, Total | 519,657 | 553,671
Available-for-sale debt securities, Gross Unrealized Loss, Total | (90,048) | (89,664)
Corporate debt securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 502,647 | 502,425
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (150,854) | (151,076)
Available-for-sale debt securities fair value, Total | 502,647 | 502,425
Available-for-sale debt securities, Gross Unrealized Loss, Total | (150,854) | (151,076)
Foreign government bonds |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 18,567 | 110,955
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | (61) | (144)
Available-for-sale debt securities, 12 Months or More, Fair Value | 88,060 | 88,616
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (11,940) | (11,384)
Available-for-sale debt securities fair value, Total | 106,627 | 199,571
Available-for-sale debt securities, Gross Unrealized Loss, Total | (12,001) | (11,528)
Asset-backed securities |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 40,712 | 42,300
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (575) | (934)
Available-for-sale debt securities fair value, Total | 40,712 | 42,300
Available-for-sale debt securities, Gross Unrealized Loss, Total | (575) | (934)
Collateralized loan obligations (“CLOs”) |  |
Schedule of Available-for-sale Debt Securities |  |
Available-for-sale debt securities, Less than 12 Months, Fair Value | 0 | 0
Available-for-sale debt securities, Gross Unrealized Loss, Less than 12 Months | 0 | 0
Available-for-sale debt securities, 12 Months or More, Fair Value | 87,851 | 612,861
Available-for-sale debt securities, Gross Unrealized Loss, 12 Months or More | (1,149) | (4,389)
Available-for-sale debt securities fair value, Total | 87,851 | 612,861
Available-for-sale debt securities, Gross Unrealized Loss, Total | $ (1,149) | $ (4,389)

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