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, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Value, Liabilities	$ 22,202	$ 19,339
Fair Value, Liabilities	300	249
Notional Value, Assets	29,696	27,266
Underwriting Purchase and Sale Commitments [Member]
Derivative [Line Items]
Notional Value, Liabilities	241	19
Notional Value, Assets	239	19
Swap [Member] | Visa Class B Shares [Member]
Derivative [Line Items]
Notional Value, Liabilities	1,100	811
Fair Value, Liabilities	$ 123	$ 106
Derivative Liability Average Remaining Maturity Period	2 years 9 months	3 years 6 months