Loans and Accounts Receivable (Details 6) pure in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) M bp	Mar. 31, 2018 USD ($) M bp
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	19	12
Aggregated Outstanding Balance	$ 168	$ 110
Card Member Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	17	11
Aggregated Outstanding Balance	$ 128	$ 81
Average Interest Rate Reduction By Class Of Financial Instrument | bp	13	11
Card Member Receivables [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts (in thousands)	2	1
Aggregated Outstanding Balance	$ 40	$ 29
Average payment term extension | M	27	28