Investment Securities - Schedule of Investment Securities (Details) - USD ($) |
Mar. 31, 2026 |
Dec. 31, 2025 |
Mar. 31, 2025 |
|---|---|---|---|
| Available-for-sale securities | |||
| Amortized Cost | $ 7,703,993,000 | $ 6,635,481,000 | $ 4,729,234,000 |
| Gross Unrealized Gains | 11,957,000 | 30,480,000 | 3,389,000 |
| Gross Unrealized Losses | (471,668,000) | (429,698,000) | (512,318,000) |
| Fair Value | 7,244,282,000 | 6,236,263,000 | 4,220,305,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 3,270,464,000 | 3,344,165,000 | 3,564,936,000 |
| Gross Unrealized Gains | 4,717,000 | 8,864,000 | 2,172,000 |
| Gross Unrealized Losses | (572,401,000) | (567,882,000) | (644,295,000) |
| Fair Value | 2,702,780,000 | 2,785,147,000 | 2,922,813,000 |
| Less: Allowance for credit losses | (257,000) | (260,000) | (446,000) |
| Held-to-maturity securities, net of allowance for credit losses | 3,270,207,000 | 3,343,905,000 | 3,564,490,000 |
| Equity securities with readily determinable fair value | |||
| Amortized Cost | 61,511,000 | 61,211,000 | 272,400,000 |
| Gross Unrealized Gains | 6,174,000 | 6,318,000 | 5,254,000 |
| Gross Unrealized Losses | (3,899,000) | (3,759,000) | (7,212,000) |
| Fair Value | 63,786,000 | 63,770,000 | 270,442,000 |
| U.S. Treasury | |||
| Available-for-sale securities | |||
| Amortized Cost | 5,000,000 | 6,999,000 | 12,943,000 |
| Gross Unrealized Gains | 14,000 | 36,000 | 51,000 |
| Gross Unrealized Losses | 0 | 0 | 0 |
| Fair Value | 5,014,000 | 7,035,000 | 12,994,000 |
| U.S. government agencies | |||
| Available-for-sale securities | |||
| Amortized Cost | 50,000,000 | 50,000,000 | 50,000,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (3,031,000) | (2,529,000) | (4,056,000) |
| Fair Value | 46,969,000 | 47,471,000 | 45,944,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 313,541,000 | 313,541,000 | 313,539,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (59,677,000) | (57,269,000) | (62,627,000) |
| Fair Value | 253,864,000 | 256,272,000 | 250,912,000 |
| Municipal | |||
| Available-for-sale securities | |||
| Amortized Cost | 175,440,000 | 162,373,000 | 190,670,000 |
| Gross Unrealized Gains | 1,145,000 | 1,643,000 | 1,063,000 |
| Gross Unrealized Losses | (2,326,000) | (1,850,000) | (3,584,000) |
| Fair Value | 174,259,000 | 162,166,000 | 188,149,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 139,117,000 | 144,192,000 | 158,307,000 |
| Gross Unrealized Gains | 277,000 | 451,000 | 303,000 |
| Gross Unrealized Losses | (2,561,000) | (2,012,000) | (4,964,000) |
| Fair Value | 136,833,000 | 142,631,000 | 153,646,000 |
| Corporate notes | |||
| Held-to-maturity securities | |||
| Amortized Cost | 29,033,000 | 35,097,000 | 56,681,000 |
| Gross Unrealized Gains | 0 | 2,000 | 14,000 |
| Gross Unrealized Losses | (259,000) | (396,000) | (1,367,000) |
| Fair Value | 28,774,000 | 34,703,000 | 55,328,000 |
| Financial issuers | |||
| Available-for-sale securities | |||
| Amortized Cost | 79,000,000 | 79,000,000 | 83,997,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (2,403,000) | (2,704,000) | (3,562,000) |
| Fair Value | 76,597,000 | 76,296,000 | 80,435,000 |
| Other | |||
| Available-for-sale securities | |||
| Amortized Cost | 1,000,000 | 1,000,000 | 1,000,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | 0 | (1,000) | 0 |
| Fair Value | 1,000,000 | 999,000 | 1,000,000 |
| Residential mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 6,420,181,000 | 5,533,710,000 | 4,067,349,000 |
| Gross Unrealized Gains | 9,567,000 | 25,926,000 | 907,000 |
| Gross Unrealized Losses | (438,090,000) | (402,953,000) | (482,256,000) |
| Fair Value | 5,991,658,000 | 5,156,683,000 | 3,586,000,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 2,613,914,000 | 2,667,371,000 | 2,825,859,000 |
| Gross Unrealized Gains | 3,964,000 | 7,503,000 | 1,072,000 |
| Gross Unrealized Losses | (492,262,000) | (491,124,000) | (555,525,000) |
| Fair Value | 2,125,616,000 | 2,183,750,000 | 2,271,406,000 |
| Commercial (multi-family) mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 326,241,000 | 280,969,000 | 58,205,000 |
| Gross Unrealized Gains | 308,000 | 570,000 | 118,000 |
| Gross Unrealized Losses | (8,052,000) | (4,986,000) | (1,696,000) |
| Fair Value | 318,497,000 | 276,553,000 | 56,627,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 6,269,000 | 6,293,000 | 6,351,000 |
| Gross Unrealized Gains | 26,000 | 72,000 | 20,000 |
| Gross Unrealized Losses | (91,000) | (92,000) | (134,000) |
| Fair Value | 6,204,000 | 6,273,000 | 6,237,000 |
| Collateralized mortgage obligations | |||
| Available-for-sale securities | |||
| Amortized Cost | 647,131,000 | 521,430,000 | 265,070,000 |
| Gross Unrealized Gains | 923,000 | 2,305,000 | 1,250,000 |
| Gross Unrealized Losses | (17,766,000) | (14,675,000) | (17,164,000) |
| Fair Value | 630,288,000 | 509,060,000 | 249,156,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 168,590,000 | 177,671,000 | 204,199,000 |
| Gross Unrealized Gains | 450,000 | 836,000 | 763,000 |
| Gross Unrealized Losses | (17,551,000) | (16,989,000) | (19,678,000) |
| Fair Value | 151,489,000 | 161,518,000 | 185,284,000 |
| Mortgage-backed securities, subprime | |||
| Available-for-sale securities | |||
| Fair Value | $ 0 | $ 0 | $ 0 |