Settlement and Other Risk Management Estimated Settlement Exposure and Portion of Uncollateralized Settlement Exposure for MasterCard-Branded Transactions (Details) - Guarantee Obligations - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Risks Inherent in Servicing Assets and Servicing Liabilities [Line Items]
Gross settlement exposure	$ 37,202	$ 39,674
Collateral held for settlement exposure	(3,734)	(3,601)
Net uncollateralized settlement exposure	$ 33,468	$ 36,073