Card Member Receivables and Card Member Loans 1 (Details) - Card Member Loans [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, reserves for credit losses	$ 20	$ 10	$ 5	$ 5
Financing receivables, net	480	687
Global Consumer Services Group [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables	500	697
Financing receivables, reserves for credit losses	20	10
Financing receivables, net	$ 480	$ 687