Transactions with Affiliates (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Parties Textuals [Abstract]
Card Member receivables and loans purchased without recourse from an affiliate	$ 225,000	$ 227,000	$ 221,000
Participation Interest Card Member Receivables Sold To Affiliates	5,700	2,600	2,800
Discount Revenue Earned From Purchased Cardmember Receivables And Loans	471	479	502
Uncharged Servicing Fees to Affiliates	253	242	212
Related Party Transaction [Line Items]
Loans to affiliates and other	10,659	14,262	$ 15,303
RFC VIII [Member]
Related Party Transaction [Line Items]
Participation interests in Card Member receivables purchased without recourse	4,000	4,100
30 Days or More Past Due [Member] | Reserves for Losses [Member]
Related Party Transaction [Line Items]
Loans to affiliates and other	0	0
Collateralized [Member]
Related Party Transaction [Line Items]
Loans to affiliates and other	$ 3,300	$ 3,600