Securities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2025 USD ($) security	Dec. 31, 2024 USD ($) security	Dec. 31, 2023 USD ($)
Debt and Equity Securities, FV-NI [Line Items]
Allowance for credit losses, available-for-sale securities	$ 0
Allowance released	$ 200,000	$ 1,000,000.0
Number of securities in an unrealized loss position | security	718	767
Debt securities, available-for-sale, unrealized loss position	$ 11,672,900,000	$ 17,832,200,000
Debt securities, available-for-sale, unrealized loss position, accumulated loss	$ 158,700,000	$ 255,100,000
Percentage of debt securities, held-to-maturity, portfolio	1	1
Gross proceeds from sale of securities		$ 2,000,000,000.0	$ 5,200,000,000
Moodys And Standard Poors A Or Higher Rating
Debt and Equity Securities, FV-NI [Line Items]
Percentage of debt securities, held-to-maturity, portfolio		0.96