Fair Value - Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ 447	$ 404	$ 927	$ 608
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	(2)	(49)	(47)	(22)
Long-term debt:
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ 17	$ 219	$ 128	$ (50)