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Fair Value Accounting (Schedule of Financial Instruments Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Assets |  |
Investment securities available for sale | $ 9,621,175 | $ 9,678,103
Mortgage loans held for sale | 62,616 | 51,136
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 615,951 | 655,127
U.S. Treasury securities |  |
Assets |  |
Investment securities available for sale | 473,890 | 471,813
Mortgage-backed securities issued by U.S. Government agencies |  |
Assets |  |
Investment securities available for sale | 817,350 | 792,749
Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 6,777,393 | 6,895,070
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 879,350 | 805,945
Corporate debt securities and other debt securities |  |
Assets |  |
Investment securities available for sale | 8,638 | 8,601
Level 1 |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 473,890 | 471,813
Other investments | 0 | 0
Mutual funds and mutual funds held in rabbi trusts | 51,147 | 42,659
SBA loans servicing asset | 0 | 0
Derivative assets | 0 | 0
Liabilities |  |
Securities sold short | 1,461 | 3,370
Mutual funds held in rabbi trusts | 36,380 | 27,944
Derivative liabilities | 0 | 0
Level 2 |  |
Assets |  |
Trading securities | 21,467 | 8,295
Investment securities available for sale | 9,147,285 | 9,206,290
Other investments | 0 | 0
Mutual funds and mutual funds held in rabbi trusts | 0 | 0
SBA loans servicing asset | 0 | 0
Derivative assets | 119,659 | 89,815
Liabilities |  |
Securities sold short | 0 | 0
Mutual funds held in rabbi trusts | 0 | 0
Derivative liabilities | 365,390 | 339,227
Level 3 |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 0 | 0
Other investments | 11,770 | 11,172
Mutual funds and mutual funds held in rabbi trusts | 0 | 0
SBA loans servicing asset | 2,234 | 2,354
Derivative assets | 0 | 0
Liabilities |  |
Securities sold short | 0 | 0
Mutual funds held in rabbi trusts | 0 | 0
Derivative liabilities | 3,937 | 3,453
Fair Value, Measurements, Recurring Basis |  |
Assets |  |
Trading securities | 21,467 | 8,295
Investment securities available for sale | 9,621,175 | 9,678,103
Mortgage loans held for sale | 62,616 | 51,136
Other investments | 11,770 | 11,172
Mutual funds and mutual funds held in rabbi trusts | 51,147 | 42,659
SBA loans servicing asset | 2,234 | 2,354
Derivative assets | 119,659 | 89,815
Liabilities |  |
Securities sold short | 1,461 | 3,370
Mutual funds held in rabbi trusts | 36,380 | 27,944
Derivative liabilities | 369,327 | 342,680
Fair Value, Measurements, Recurring Basis | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Trading securities | 2,875 | 2,991
Investment securities available for sale | 615,951 | 655,127
Fair Value, Measurements, Recurring Basis | Other mortgage-backed securities |  |
Assets |  |
Trading securities | 2,685 | 3,185
Fair Value, Measurements, Recurring Basis | State and municipal securities |  |
Assets |  |
Trading securities | 0 | 48
Fair Value, Measurements, Recurring Basis | Asset-backed securities |  |
Assets |  |
Trading securities | 15,907 | 2,071
Fair Value, Measurements, Recurring Basis | U.S. Treasury securities |  |
Assets |  |
Investment securities available for sale | 473,890 | 471,813
Fair Value, Measurements, Recurring Basis | U.S. Government agency securities |  |
Assets |  |
Investment securities available for sale | 48,603 | 48,798
Fair Value, Measurements, Recurring Basis | Mortgage-backed securities issued by U.S. Government agencies |  |
Assets |  |
Investment securities available for sale | 817,350 | 792,749
Fair Value, Measurements, Recurring Basis | Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 6,777,393 | 6,895,070
Fair Value, Measurements, Recurring Basis | Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 879,350 | 805,945
Fair Value, Measurements, Recurring Basis | Corporate debt securities and other debt securities |  |
Assets |  |
Investment securities available for sale | 8,638 | 8,601
Fair Value, Measurements, Recurring Basis | Level 1 |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 473,890 | 471,813
Mortgage loans held for sale | 0 | 0
Other investments | 0 | 0
Mutual funds and mutual funds held in rabbi trusts | 51,147 | 42,659
SBA loans servicing asset | 0 | 0
Derivative assets | 0 | 0
Liabilities |  |
Securities sold short | 1,461 | 3,370
Mutual funds held in rabbi trusts | 36,380 | 27,944
Derivative liabilities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Other mortgage-backed securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | State and municipal securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Asset-backed securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | U.S. Treasury securities |  |
Assets |  |
Investment securities available for sale | 473,890 | 471,813
Fair Value, Measurements, Recurring Basis | Level 1 | U.S. Government agency securities |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Mortgage-backed securities issued by U.S. Government agencies |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 1 | Corporate debt securities and other debt securities |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 2 |  |
Assets |  |
Trading securities | 21,467 | 8,295
Investment securities available for sale | 9,147,285 | 9,206,290
Mortgage loans held for sale | 62,616 | 51,136
Other investments | 0 | 0
Mutual funds and mutual funds held in rabbi trusts | 0 | 0
SBA loans servicing asset | 0 | 0
Derivative assets | 119,659 | 89,815
Liabilities |  |
Securities sold short | 0 | 0
Mutual funds held in rabbi trusts | 0 | 0
Derivative liabilities | 365,390 | 339,227
Fair Value, Measurements, Recurring Basis | Level 2 | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Trading securities | 2,875 | 2,991
Investment securities available for sale | 615,951 | 655,127
Fair Value, Measurements, Recurring Basis | Level 2 | Other mortgage-backed securities |  |
Assets |  |
Trading securities | 2,685 | 3,185
Fair Value, Measurements, Recurring Basis | Level 2 | State and municipal securities |  |
Assets |  |
Trading securities | 0 | 48
Fair Value, Measurements, Recurring Basis | Level 2 | Asset-backed securities |  |
Assets |  |
Trading securities | 15,907 | 2,071
Fair Value, Measurements, Recurring Basis | Level 2 | U.S. Treasury securities |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 2 | U.S. Government agency securities |  |
Assets |  |
Investment securities available for sale | 48,603 | 48,798
Fair Value, Measurements, Recurring Basis | Level 2 | Mortgage-backed securities issued by U.S. Government agencies |  |
Assets |  |
Investment securities available for sale | 817,350 | 792,749
Fair Value, Measurements, Recurring Basis | Level 2 | Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 6,777,393 | 6,895,070
Fair Value, Measurements, Recurring Basis | Level 2 | Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 879,350 | 805,945
Fair Value, Measurements, Recurring Basis | Level 2 | Corporate debt securities and other debt securities |  |
Assets |  |
Investment securities available for sale | 8,638 | 8,601
Fair Value, Measurements, Recurring Basis | Level 3 |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 0 | 0
Mortgage loans held for sale | 0 | 0
Other investments | 11,770 | 11,172
Mutual funds and mutual funds held in rabbi trusts | 0 | 0
SBA loans servicing asset | 2,234 | 2,354
Derivative assets | 0 | 0
Liabilities |  |
Securities sold short | 0 | 0
Mutual funds held in rabbi trusts | 0 | 0
Derivative liabilities | 3,937 | 3,453
Fair Value, Measurements, Recurring Basis | Level 3 | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Trading securities | 0 | 0
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Other mortgage-backed securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | State and municipal securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Asset-backed securities |  |
Assets |  |
Trading securities | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | U.S. Treasury securities |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | U.S. Government agency securities |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Mortgage-backed securities issued by U.S. Government agencies |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Assets |  |
Investment securities available for sale | 0 | 0
Fair Value, Measurements, Recurring Basis | Level 3 | Corporate debt securities and other debt securities |  |
Assets |  |
Investment securities available for sale | $ 0 | $ 0

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