Reserves For Losses (Textuals) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cardmember receivables reserves for losses - other	$ (73)	$ (125)
Cardmember loans reserves for losses - other	(77)	(77)
Cardmember receivables net write-offs	(487)	(406)
Cardmember loans net write-offs - principal	(970)	(1,375)
Allowance for Cardmember Receivables and Reserves, Recoveries of Bad Debts	292	255
Allowance for Cardmember Loans and Reserves, Recoveries of Bad Debts	382	444
UnauthorizedTransactionsMember [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cardmember receivables reserves for losses - other	(100)	(123)
Cardmember loans reserves for losses - other	(84)	(76)
ForeignCurrencyTranslationAdjustmentsMember [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cardmember receivables reserves for losses - other	4	0
Cardmember loans reserves for losses - other	10	(1)
CardmemberBankruptcyReservesMember [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cardmember receivables reserves for losses - other	18	0
Cardmember loans reserves for losses - other	4	0
OtherItemsMember [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cardmember receivables reserves for losses - other	5	(2)
Cardmember loans reserves for losses - other	$ (7)	$ 0