Investment Securities - Schedule of Investment Securities (Details) - USD ($) |
Jun. 30, 2025 |
Dec. 31, 2024 |
Jun. 30, 2024 |
|---|---|---|---|
| Available-for-sale securities | |||
| Amortized Cost | $ 5,389,193,000 | $ 4,725,539,000 | $ 4,906,690,000 |
| Gross Unrealized Gains | 7,097,000 | 2,071,000 | 1,393,000 |
| Gross Unrealized Losses | (510,575,000) | (586,128,000) | (578,126,000) |
| Fair Value | 4,885,715,000 | 4,141,482,000 | 4,329,957,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 3,502,584,000 | 3,613,720,000 | 3,756,415,000 |
| Gross Unrealized Gains | 3,041,000 | 1,066,000 | 517,000 |
| Gross Unrealized Losses | (636,210,000) | (704,236,000) | (696,465,000) |
| Fair Value | 2,869,415,000 | 2,910,550,000 | 3,060,467,000 |
| Less: Allowance for credit losses | (398,000) | (457,000) | (491,000) |
| Held-to-maturity securities, net of allowance for credit losses | 3,502,186,000 | 3,613,263,000 | 3,755,924,000 |
| Equity securities with readily determinable fair value | |||
| Amortized Cost | 273,789,000 | 220,758,000 | 117,674,000 |
| Gross Unrealized Gains | 7,047,000 | 2,905,000 | 2,882,000 |
| Gross Unrealized Losses | (7,114,000) | (8,251,000) | (8,383,000) |
| Fair Value | 273,722,000 | 215,412,000 | 112,173,000 |
| U.S. Treasury | |||
| Available-for-sale securities | |||
| Amortized Cost | 12,979,000 | 37,858,000 | 102,721,000 |
| Gross Unrealized Gains | 39,000 | 49,000 | 5,000 |
| Gross Unrealized Losses | 0 | 0 | (14,000) |
| Fair Value | 13,018,000 | 37,907,000 | 102,712,000 |
| 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 | (4,176,000) | (5,055,000) | (4,808,000) |
| Fair Value | 45,824,000 | 44,945,000 | 45,192,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 313,540,000 | 313,539,000 | 336,458,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (64,071,000) | (69,127,000) | (70,928,000) |
| Fair Value | 249,469,000 | 244,412,000 | 265,530,000 |
| Municipal | |||
| Available-for-sale securities | |||
| Amortized Cost | 182,761,000 | 188,405,000 | 151,347,000 |
| Gross Unrealized Gains | 1,120,000 | 528,000 | 390,000 |
| Gross Unrealized Losses | (3,237,000) | (4,340,000) | (5,129,000) |
| Fair Value | 180,644,000 | 184,593,000 | 146,608,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 156,753,000 | 161,016,000 | 166,400,000 |
| Gross Unrealized Gains | 296,000 | 243,000 | 155,000 |
| Gross Unrealized Losses | (4,030,000) | (5,290,000) | (6,789,000) |
| Fair Value | 153,019,000 | 155,969,000 | 159,766,000 |
| Corporate notes | |||
| Held-to-maturity securities | |||
| Amortized Cost | 53,531,000 | 56,851,000 | 57,199,000 |
| Gross Unrealized Gains | 75,000 | 8,000 | 0 |
| Gross Unrealized Losses | (1,000,000) | (1,870,000) | (3,211,000) |
| Fair Value | 52,606,000 | 54,989,000 | 53,988,000 |
| Financial issuers | |||
| Available-for-sale securities | |||
| Amortized Cost | 82,000,000 | 83,997,000 | 83,996,000 |
| Gross Unrealized Gains | 0 | 0 | 0 |
| Gross Unrealized Losses | (3,199,000) | (3,828,000) | (7,011,000) |
| Fair Value | 78,801,000 | 80,169,000 | 76,985,000 |
| 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 | (2,000) | (7,000) | (10,000) |
| Fair Value | 998,000 | 993,000 | 990,000 |
| Residential mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 4,618,492,000 | 4,106,641,000 | 4,320,215,000 |
| Gross Unrealized Gains | 3,960,000 | 284,000 | 361,000 |
| Gross Unrealized Losses | (478,768,000) | (553,287,000) | (541,742,000) |
| Fair Value | 4,143,684,000 | 3,553,638,000 | 3,778,834,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 2,775,981,000 | 2,864,927,000 | 2,962,721,000 |
| Gross Unrealized Gains | 1,637,000 | 0 | 0 |
| Gross Unrealized Losses | (548,063,000) | (605,014,000) | (591,601,000) |
| Fair Value | 2,229,555,000 | 2,259,913,000 | 2,371,120,000 |
| Commercial (multi-family) mortgage-backed securities | |||
| Available-for-sale securities | |||
| Amortized Cost | 130,464,000 | 19,064,000 | 18,096,000 |
| Gross Unrealized Gains | 115,000 | 23,000 | 8,000 |
| Gross Unrealized Losses | (3,634,000) | (755,000) | (626,000) |
| Fair Value | 126,945,000 | 18,332,000 | 17,478,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 6,333,000 | 6,364,000 | 6,390,000 |
| Gross Unrealized Gains | 51,000 | 0 | 0 |
| Gross Unrealized Losses | (113,000) | (252,000) | (300,000) |
| Fair Value | 6,271,000 | 6,112,000 | 6,090,000 |
| Collateralized mortgage obligations | |||
| Available-for-sale securities | |||
| Amortized Cost | 311,497,000 | 238,574,000 | 179,315,000 |
| Gross Unrealized Gains | 1,863,000 | 1,187,000 | 629,000 |
| Gross Unrealized Losses | (17,559,000) | (18,856,000) | (18,786,000) |
| Fair Value | 295,801,000 | 220,905,000 | 161,158,000 |
| Held-to-maturity securities | |||
| Amortized Cost | 196,446,000 | 211,023,000 | 227,247,000 |
| Gross Unrealized Gains | 982,000 | 815,000 | 362,000 |
| Gross Unrealized Losses | (18,933,000) | (22,683,000) | (23,636,000) |
| Fair Value | 178,495,000 | 189,155,000 | 203,973,000 |
| Mortgage-backed securities, subprime | |||
| Available-for-sale securities | |||
| Fair Value | $ 0 | $ 0 | $ 0 |