Derivative Instruments - Asset and Liability Management Derivative Positions of Company (Parenthetical) (Detail) - Asset and Liability Management Positions [Member] - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Notional Value, Liabilities	$ 19,709	$ 21,623
Fair Value, Liabilities	348	472
Notional Value, Assets	27,967	20,217
Underwriting Purchase and Sale Commitments [Member]
Derivative [Line Items]
Notional Value, Liabilities	45	58
Notional Value, Assets	45	58
Swap [Member] | Visa Class B [Member]
Derivative [Line Items]
Notional Value, Liabilities	416	332
Fair Value, Liabilities	$ 50	$ 44
Derivative Liability Average Remaining Maturity Period	3 years 3 months 4 days	3 years 9 months