Loans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest receivable	$ 2,200		$ 2,200		$ 1,900
Commitments to lend on loans modified in TDRs	$ 75	$ 214	$ 75	$ 214
Financing Receivable, Pledged Status [Extensible Enumeration]	Asset Pledged as Collateral [Member]		Asset Pledged as Collateral [Member]
Net loans held for investment	$ 299,825		$ 299,825		299,091
Loans held for sale	742		742		203
Federal Home Loan banks
Financing Receivable, Allowance for Credit Loss [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	31,600		31,600		19,900
Net loans held for investment	7,800		7,800		9,800
Federal Reserve Discount Window
Financing Receivable, Allowance for Credit Loss [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	40,900		40,900		19,700
Net loans held for investment	69,800		69,800		$ 34,100
Domestic credit card: | Domestic Credit Card and Commercial Banking Portfolios [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans converted to term during period	$ 101	$ 51	$ 443	$ 383