Prepaid Expenses and Other Assets Schedule of Other Assets (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Customer and merchant incentives	$ 551	$ 531
Nonmarketable equity investments	164	229
Income taxes receivable	81	78
Other	91	64
Total other assets	$ 887	$ 902