Loans and Accounts Receivable (Details 6) account in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) account bp	Dec. 31, 2018 USD ($) bp account	Dec. 31, 2017 USD ($) account bp
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	87	57	39
Outstanding Balance | $	$ 812	$ 487	$ 307
Card Member Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	78	51	33
Outstanding Balance | $	$ 602	$ 377	$ 224
Average Interest Rate Reduction | bp	13	12	10
Card Member Receivables [Member]
Financing Receivable, Modifications [Line Items]
Number of Accounts | account	9	6	6
Outstanding Balance | $	$ 210	$ 110	$ 83
Average Payment Term Extension	26 months	28 months	28 months