Loans and Accounts Receivable (Details 7) account in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) account	Dec. 31, 2018 USD ($) account	Dec. 31, 2017 USD ($) account
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	16	12	9
Aggregated outstanding balance upon payment default | $	$ 106	$ 57	$ 46
Card Member Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	12	8	6
Aggregated outstanding balance upon payment default | $	$ 86	$ 46	$ 39
Card Member Receivables [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	4	4	3
Aggregated outstanding balance upon payment default | $	$ 20	$ 11	$ 7