Fair Value - Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ (52)	$ (795)	$ (979)	$ (1,403)
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	(134)	117	(87)	95
Long-term debt:
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ 471	$ (406)	$ 343	$ (356)