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Investment Securities Available for Sale - Schedule Of Unrealized Loss On Investments (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
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Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | $ 1,088,423 | $ 409,725
Less than 12 months, gross unrealized losses | (5,877) | (2,666)
12 months or longer, fair value | 7,580,118 | 7,513,154
12 months or longer, gross unrealized losses | (1,459,815) | (1,331,466)
Total, fair value | 8,668,541 | 7,922,879
Total, gross unrealized losses | (1,465,692) | (1,334,132)
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 465,387 |
Less than 12 months, gross unrealized losses | (1,133) |
12 months or longer, fair value | 0 |
12 months or longer, gross unrealized losses | 0 |
Total, fair value | 465,387 |
Total, gross unrealized losses | (1,133) |
U.S. Government agency securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 0 | 0
Less than 12 months, gross unrealized losses | 0 | 0
12 months or longer, fair value | 28,783 | 28,940
12 months or longer, gross unrealized losses | (1,210) | (1,053)
Total, fair value | 28,783 | 28,940
Total, gross unrealized losses | (1,210) | (1,053)
Mortgage-backed securities issued by U.S. Government agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 132,795 | 159,402
Less than 12 months, gross unrealized losses | (712) | (1,268)
12 months or longer, fair value | 696,870 | 565,358
12 months or longer, gross unrealized losses | (111,370) | (96,717)
Total, fair value | 829,665 | 724,760
Total, gross unrealized losses | (112,082) | (97,985)
Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 129,505 | 215,917
Less than 12 months, gross unrealized losses | (2,158) | (1,193)
12 months or longer, fair value | 6,005,861 | 6,045,914
12 months or longer, gross unrealized losses | (1,198,664) | (1,093,019)
Total, fair value | 6,135,366 | 6,261,831
Total, gross unrealized losses | (1,200,822) | (1,094,212)
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 0 | 0
Less than 12 months, gross unrealized losses | 0 | 0
12 months or longer, fair value | 564,940 | 587,595
12 months or longer, gross unrealized losses | (111,832) | (104,892)
Total, fair value | 564,940 | 587,595
Total, gross unrealized losses | (111,832) | (104,892)
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 360,736 | 34,406
Less than 12 months, gross unrealized losses | (1,874) | (205)
12 months or longer, fair value | 274,840 | 276,675
12 months or longer, gross unrealized losses | (36,529) | (35,448)
Total, fair value | 635,576 | 311,081
Total, gross unrealized losses | (38,403) | (35,653)
Corporate debt securities and other debt securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 0 | 0
Less than 12 months, gross unrealized losses | 0 | 0
12 months or longer, fair value | 8,824 | 8,672
12 months or longer, gross unrealized losses | (210) | (337)
Total, fair value | 8,824 | 8,672
Total, gross unrealized losses | $ (210) | $ (337)

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