Fair Value - Changes in FV under the FV Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ 204	$ 480
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	71	(191)
Long-term debt:
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value gains (losses)	$ (269)	$ 1,100