Loans and Accounts Receivable (Details 6) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts	19,000	13,000	38,000	25,000
Outstanding Balances	$ 187	$ 113	$ 355	$ 223
Card Member Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts	17,000	12,000	34,000	23,000
Outstanding Balances	$ 137	$ 88		$ 169
Average Interest Rate Reduction (as a percentage)	13.00%	12.00%	13.00%	12.00%
Card Member Receivables [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts		1,000	4,000	2,000
Outstanding Balances	$ 50	$ 25	$ 90	$ 54
Average Payment Term Extension (in months)	26 months	28 months	27 months	28 months