Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Supplemental cash flow information - Noncash activities
Available-for-sale debt securities purchased from securitization of LHFS	$ 1,506	$ 256
Held-to-maturity debt securities purchased from securitization of LHFS	732	17,600
Transfers from loans to LHFS	6,820	14,842
Transfers from available-for-sale debt securities to held-to-maturity debt securities	$ 48,591	$ 41,298