Card Member Receivables and Loans (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net volume of Card Member receivables purchased	$ 61,000	$ 57,000
Net volume of Card Member loans purchased	1,100	$ 1,000
Deferred discount revenue on Card Member receivable	30		$ 27
RFC VIII [Member]
Related Party Transaction [Line Items]
Participation Interests In Card Member Receivables Purchased	$ 4,600		$ 4,000