Allowance for Credit Losses and Reserve for Unfunded Lending Commitments - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit loss	$ 13,240	$ 11,430
Uncollectible portion of billed finance charges and fees	946	629	$ 1,100
Allowance for credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (Decrease) in Allowance for Credit Loss	1,800
Allowance for credit loss	$ 13,240	$ 11,430	$ 15,564	$ 7,208