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Investment Securities (Narrative) (Details) | 12 Months Ended
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Dec. 31, 2022 USD ($) security | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
Debt Securities, Available-for-sale [Line Items] |  |  |
Equity securities without readily determinable fair values | $ 43,800,000 | $ 37,500,000 |
Upward adjustments of equity securities without readily determinable fair values | 0 | 0 | $ 401,000
Downward adjustments of equity securities without readily determinable fair values | 0 | 0 | 0
Impairment of equity securities without readily determinable fair values | 12,158,000 | 2,415,000 | 2,995,000
Income tax (benefit) expense | 190,873,000 | 171,645,000 | 96,791,000
Pledged securities | $ 2,800,000,000 | 2,600,000,000 |
Number of securities by a single non-government sponsored issuer exceeding 10% of shareholders' equity | security | 0 |  |
Investment securities |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |
Income tax (benefit) expense | $ (5,400,000) | $ (282,000) | $ (513,000)

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