Investment Securities - Schedule of Investment Securities (Details) - USD ($) |
Jun. 30, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
|---|---|---|---|
| Available-for-sale securities | |||
| Amortized Cost | $ 8,069,111,000 | $ 6,635,481,000 | $ 5,389,193,000 |
| Gross Unrealized Gains | 11,385,000 | 30,480,000 | 7,097,000 |
| Gross Unrealized Losses | (492,951,000) | (429,698,000) | (510,575,000) |
| Fair Value | 7,587,545,000 | 6,236,263,000 | 4,885,715,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 3,196,672,000 | 3,344,165,000 | 3,502,584,000 |
| Gross Unrealized Gains | 5,184,000 | 8,864,000 | 3,041,000 |
| Gross Unrealized Losses | (566,895,000) | (567,882,000) | (636,210,000) |
| Fair Value | 2,634,961,000 | 2,785,147,000 | 2,869,415,000 |
| Less: Allowance for credit losses | (220,000) | (260,000) | (398,000) |
| Held-to-maturity securities, net of allowance for credit losses | 3,196,452,000 | 3,343,905,000 | 3,502,186,000 |
| Equity securities with readily determinable fair value | |||
| Amortized Cost | 61,989,000 | 61,211,000 | 273,789,000 |
| Gross Unrealized Gains | 7,836,000 | 6,318,000 | 7,047,000 |
| Gross Unrealized Losses | (4,010,000) | (3,759,000) | (7,114,000) |
| Fair Value | 65,815,000 | 63,770,000 | 273,722,000 |
| U.S. Treasury | |||
| Available-for-sale securities | |||
| Amortized Cost | 5,000,000 | 6,999,000 | 12,979,000 |
| Gross Unrealized Gains | 5,000 | 36,000 | 39,000 |
| Gross Unrealized Losses | 0 | 0 | 0 |
| Fair Value | 5,005,000 | 7,035,000 | 13,018,000 |
| 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 | (3,498,000) | (2,529,000) | (4,176,000) |
| Fair Value | 46,502,000 | 47,471,000 | 45,824,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 313,542,000 | 313,541,000 | 313,540,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (60,052,000) | (57,269,000) | (64,071,000) |
| Fair Value | 253,490,000 | 256,272,000 | 249,469,000 |
| Municipal | |||
| Available-for-sale securities | |||
| Amortized Cost | 171,880,000 | 162,373,000 | 182,761,000 |
| Gross Unrealized Gains | 1,154,000 | 1,643,000 | 1,120,000 |
| Gross Unrealized Losses | (1,886,000) | (1,850,000) | (3,237,000) |
| Fair Value | 171,148,000 | 162,166,000 | 180,644,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 134,234,000 | 144,192,000 | 156,753,000 |
| Gross Unrealized Gains | 248,000 | 451,000 | 296,000 |
| Gross Unrealized Losses | (1,946,000) | (2,012,000) | (4,030,000) |
| Fair Value | 132,536,000 | 142,631,000 | 153,019,000 |
| Corporate notes | |||
| Held-to-maturity securities | |||
| Amortized Cost | 25,982,000 | 35,097,000 | 53,531,000 |
| Gross Unrealized Gains | 0 | 2,000 | 75,000 |
| Gross Unrealized Losses | (133,000) | (396,000) | (1,000,000) |
| Fair Value | 25,849,000 | 34,703,000 | 52,606,000 |
| Financial issuers | |||
| Available-for-sale securities | |||
| Amortized Cost | 75,000,000 | 79,000,000 | 82,000,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (1,973,000) | (2,704,000) | (3,199,000) |
| Fair Value | 73,027,000 | 76,296,000 | 78,801,000 |
| Other | |||
| Available-for-sale securities | |||
| Amortized Cost | 1,000,000 | 1,000,000 | 1,000,000 |
| Gross Unrealized Gains | 18,000 | 0 | 0 |
| Gross Unrealized Losses | 0 | (1,000) | (2,000) |
| Fair Value | 1,018,000 | 999,000 | 998,000 |
| Residential mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 6,602,806,000 | 5,533,710,000 | 4,618,492,000 |
| Gross Unrealized Gains | 9,694,000 | 25,926,000 | 3,960,000 |
| Gross Unrealized Losses | (454,231,000) | (402,953,000) | (478,768,000) |
| Fair Value | 6,158,269,000 | 5,156,683,000 | 4,143,684,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 2,557,267,000 | 2,667,371,000 | 2,775,981,000 |
| Gross Unrealized Gains | 4,665,000 | 7,503,000 | 1,637,000 |
| Gross Unrealized Losses | (487,151,000) | (491,124,000) | (548,063,000) |
| Fair Value | 2,074,781,000 | 2,183,750,000 | 2,229,555,000 |
| Commercial (multi-family) mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 344,436,000 | 280,969,000 | 130,464,000 |
| Gross Unrealized Gains | 27,000 | 570,000 | 115,000 |
| Gross Unrealized Losses | (10,474,000) | (4,986,000) | (3,634,000) |
| Fair Value | 333,989,000 | 276,553,000 | 126,945,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 6,210,000 | 6,293,000 | 6,333,000 |
| Gross Unrealized Gains | 0 | 72,000 | 51,000 |
| Gross Unrealized Losses | (115,000) | (92,000) | (113,000) |
| Fair Value | 6,095,000 | 6,273,000 | 6,271,000 |
| Collateralized mortgage obligations | |||
| Available-for-sale securities | |||
| Amortized Cost | 818,989,000 | 521,430,000 | 311,497,000 |
| Gross Unrealized Gains | 487,000 | 2,305,000 | 1,863,000 |
| Gross Unrealized Losses | (20,889,000) | (14,675,000) | (17,559,000) |
| Fair Value | 798,587,000 | 509,060,000 | 295,801,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 159,437,000 | 177,671,000 | 196,446,000 |
| Gross Unrealized Gains | 271,000 | 836,000 | 982,000 |
| Gross Unrealized Losses | (17,498,000) | (16,989,000) | (18,933,000) |
| Fair Value | 142,210,000 | 161,518,000 | 178,495,000 |
| Mortgage-backed securities, subprime | |||
| Available-for-sale securities | |||
| Fair Value | $ 0 | $ 0 | $ 0 |