Card Member Receivables and Card Member Loans (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable Segment [Abstract]
Less: Reserve for losses	$ 162	$ 167	$ 145	$ 110
Card Member receivables, net	25,395	24,429
Net of deferred discount revenues	75	68
Card Member Receivables [Member]
Accounts Receivable Segment [Abstract]
Card Member receivables	25,557	24,596
Less: Reserve for losses	162	167
Card Member receivables, net	25,395	24,429
Global Consumer Services Group [Member] | Card Member Receivables [Member]
Accounts Receivable Segment [Abstract]
Card Member receivables	9,847	8,485
Global Commercial Services [Member] | Card Member Receivables [Member]
Accounts Receivable Segment [Abstract]
Card Member receivables	$ 15,710	$ 16,111