Securities (Narrative) (Details)	12 Months Ended
Dec. 31, 2022 USD ($)	Dec. 31, 2024 USD ($) Security	Dec. 31, 2023 USD ($) Security
Debt and Equity Securities, FV-NI [Line Items]
Securities with an aggregate fair value		$ 4,608,320,000	$ 4,276,643,000
Securities available for sale, amortized cost		5,774,133,000	5,496,718,000
Securities classified as trading		0	$ 0
Allowance for credit loss		$ 0
Securities that met the criteria of a credit loss event \| Security		0
Number of securities with market values below their cost basis \| Security		729	698
Asset Pledged as Collateral without Right [Member]
Debt and Equity Securities, FV-NI [Line Items]
Securities pledged as collateral		$ 3,900,000,000	$ 4,700,000,000
Available for Sale and Held to Maturity [Member]
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost of securities excluding accrued interest		29,800,000	27,400,000
Securities with an aggregate fair value	$ 561,800,000	$ 0	$ 0
Unrealized loss	15,400,000
Securities available for sale, amortized cost	$ 561,800,000

Available for sale securities amortized cost excluding accrued interest.

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Amount of allowance for credit loss of accounts and financing receivables. Includes, but is not limited to, notes and loan receivable.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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