Loans and Accounts Receivable (Details 7) account in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) account	Sep. 30, 2018 USD ($) account	Sep. 30, 2019 USD ($) account	Sep. 30, 2018 USD ($) account
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts | account	5	3	12	8
Aggregated Outstanding Balance Upon Default | $	$ 28	$ 15	$ 72	$ 37
Card Member Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts | account	4	2	9	5
Aggregated Outstanding Balance Upon Default | $	$ 23	$ 13	$ 59	$ 30
Card Member Receivables [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts | account	1	1	3	3
Aggregated Outstanding Balance Upon Default | $	$ 5	$ 2	$ 13	$ 7