Securities (Narrative) (Details)	3 Months Ended
Mar. 31, 2026 USD ($) security	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($) security
Debt and Equity Securities, FV-NI [Line Items]
Provision for credit losses	$ 0	$ (200,000)
Allowance for credit losses for AFS securities	$ 0		$ 0
Number of securities in an unrealized loss position \| security	888		718
Total fair value	$ 18,087,000,000		$ 11,672,900,000
Debt securities, unrealized losses	$ 203,900,000		$ 158,700,000
Percentage of debt securities, held-to-maturity, portfolio	1		1
Rating of A or higher
Debt and Equity Securities, FV-NI [Line Items]
Percentage of debt securities, held-to-maturity, portfolio	0.95		0.96

Debt Securities, Held-To-Maturity, Percent Of Portfolio

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Number of Securities, Unrealized Losses Position

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Amount excluding accrued interest, of allowance for credit loss on 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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Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss 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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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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