Loans and Accounts Receivable (Details 1) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts receivable segment information
Card Member receivables	$ 54,241	$ 54,047
Less: Reserve for losses	565	521	$ 491	$ 467
Card Member receivables, net	53,676	53,526
Other receivables, net	3,194	3,209
Accounts Receivable and Loans Textuals [Abstract]
Other receivables, reserves	31	31
Variable Interest Enterprise [Member]
Accounts receivable segment information
Card Member receivables	7,807	8,919
Non United States [Member]
Accounts receivable segment information
Card Member receivables	0	0
U S Consumer Services [Member]
Accounts receivable segment information
Card Member receivables	11,659	13,143
U S Consumer Services [Member] | Variable Interest Enterprise [Member]
Accounts Receivable and Loans Textuals [Abstract]
Gross Card Member receivables available to settle the obligations of a variable interest entity	7,800	8,900
International Consumer and Network Services [Member]
Accounts receivable segment information
Card Member receivables	7,071	7,803
Global Commercial Services [Member]
Accounts receivable segment information
Card Member receivables	$ 35,511	$ 33,101