Loans and Accounts Receivable (Details 7) pure in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	12	9	10
Aggregated Outstanding Balance Upon Payment Default	$ 57	$ 46	$ 45
Card Member Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	8	6	7
Aggregated Outstanding Balance Upon Payment Default	$ 46	$ 39	$ 41
Card Member Receivables [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	4	3	3
Aggregated Outstanding Balance Upon Payment Default	$ 11	$ 7	$ 4