Investment Securities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Investments, Debt and Equity Securities [Abstract]
Approximate percentage rated at least AA+	99.00%
Investment securities, allowance for credit losses	$ 78	$ 118	$ 106
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Reduction in allowance for credit losses related to sales of securities	$ 31	$ 17