Loans - Credit Card Loan Portfolio, Payment Status of FDMs and Defaults of FDMs (Details) - Credit card $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) loan_payment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Financing Receivable, Modified [Line Items]
Amortized cost of FDMs during the last 12 months	$ 2,084	$ 926	$ 648
FDMs that defaulted	$ 111	0	0
Number of payments past due considered payment default for modified loans | loan_payment	2
Current and less than 30 days past due and still accruing
Financing Receivable, Modified [Line Items]
Amortized cost of FDMs during the last 12 months	$ 1,801	811	558
30–89 days past due and still accruing
Financing Receivable, Modified [Line Items]
Amortized cost of FDMs during the last 12 months	179	74	59
90 or more days past due and still accruing
Financing Receivable, Modified [Line Items]
Amortized cost of FDMs during the last 12 months	$ 104	$ 41	$ 31