Derivative Instruments - Asset and Liability Management Derivative Positions of Company (Parenthetical) (Detail) - Asset and Liability Management Positions [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Notional Value, Liabilities	$ 20,511	$ 21,623
Fair Value, Liabilities	375	472
Notional Value, Assets	25,233	20,217
Underwriting Purchase and Sale Commitments [Member]
Derivative [Line Items]
Notional Value, Liabilities	111	58
Notional Value, Assets	111	58
Swap [Member] | Visa Class B Shares [Member]
Derivative [Line Items]
Notional Value, Liabilities	571	332
Fair Value, Liabilities	$ 62	$ 44
Derivative Liability Average Remaining Maturity Period	3 years 4 days	3 years 9 months