Derivative Financial Instruments (Schedule of Differences Between the Gains (Losses) on the Derivative and The Gains (Losses) on the Hedged Item) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	$ 9,884	$ 9,649	$ 9,594
Derivatives designed as cash flow value hedges
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	162	126	9
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	(4)	(5)	(7)
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	9	9	3
Interest-rate contracts | Derivatives designed as cash flow value hedges
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	9	4	9
Interest-rate contracts | Net interest revenue | Derivatives designed as cash flow value hedges
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	(4)	(5)	(7)
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	3	3	3
Foreign exchange contracts | Derivatives designed as cash flow value hedges
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	153	122	0
Foreign exchange contracts | Net interest revenue | Derivatives designed as cash flow value hedges
Derivative [Line Items]
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	0	0	0
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$ 6	$ 6	$ 0