Reserves For Losses (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Card Member Receivables, Recoveries of Bad Debts	$ 401	$ 358	$ 402
Allowance for Card Member Loans, Recoveries of Bad Debts	418	428	452
Allowance for Card Member Receivables, Recoveries of Bad Debts - TDR	60	15	12
Allowance for Card Member Loans, Recoveries of Bad Debts - TDR	41	(10)	(1)
Card Member loans reserves for losses - other	10	12	(22)
Unauthorized Transactions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Card Member receivables reserves for losses - other		(7)
Card Member loans reserves for losses - other		(6)
Foreign Currency Translation Adjustments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Card Member receivables reserves for losses - other	(16)	(15)	(4)
Card Member loans reserves for losses - other	(20)	(17)	(12)
Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Card Member receivables reserves for losses - other	$ (11)	$ (8)	$ (17)