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Investment Securities - Summary of Investment Securities (Detail) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | $ 9,720,415 | $ 9,668,422
Unrealized Gains |  | 12,952 | 50,673
Unrealized Losses |  | (725,900) | (759,366)
Allowance for Credit Losses |  | (867) | 0
Fair Value | [1] | 9,006,600 | 8,959,729
Debt Securities, Available-For-Sale |  |  |
Schedule of Investments [Line Items] |  |  |
Interest receivable |  | 35,200 | 42,500
Government agency debentures |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 222,767 | 302,212
Unrealized Gains |  | 0 | 0
Unrealized Losses |  | (36,341) | (37,579)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 186,426 | 264,633
Municipal bonds and notes |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 123,885 | 1,626,126
Unrealized Gains |  | 2 | 8
Unrealized Losses |  | (13,011) | (52,901)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 110,876 | 1,573,233
Agency CMO |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 32,193 | 52,994
Unrealized Gains |  | 0 | 0
Unrealized Losses |  | (3,150) | (4,053)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 29,043 | 48,941
Agency MBS |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 4,760,541 | 3,568,140
Unrealized Gains |  | 11,654 | 32,461
Unrealized Losses |  | (252,410) | (253,503)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 4,519,785 | 3,347,098
Agency CMBS |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 3,400,021 | 2,569,438
Unrealized Gains |  | 84 | 18,204
Unrealized Losses |  | (365,713) | (299,571)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 3,034,392 | 2,288,071
CMBS |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 630,985 | 788,478
Unrealized Gains |  | 411 | 0
Unrealized Losses |  | (6,008) | (24,729)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 625,388 | 763,749
Corporate debt |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 496,087 | 704,569
Unrealized Gains |  | 801 | 0
Unrealized Losses |  | (43,755) | (82,414)
Allowance for Credit Losses |  | (867) | 0
Fair Value |  | 452,266 | 622,155
Private label MBS |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 44,081 | 46,635
Unrealized Gains |  | 0 | 0
Unrealized Losses |  | (4,862) | (3,827)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | 39,219 | 42,808
Other |  |  |
Schedule of Investments [Line Items] |  |  |
Total available-for-sale |  | 9,855 | 9,830
Unrealized Gains |  | 0 | 0
Unrealized Losses |  | (650) | (789)
Allowance for Credit Losses |  | 0 | 0
Fair Value |  | $ 9,205 | $ 9,041
[1] | Investment securities available-for-sale had an amortized cost basis of $9,720,415 at December 31, 2024, and $9,668,422 at December 31, 2023.

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