Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Total		$ 4,088,019	$ 4,135,130
Interest rate contracts [Member]
Derivative [Line Items]
Total		2,591,074	2,805,579
Interest Rate Futures and Forwards [Member]
Derivative [Line Items]
Total		353,125	501,635
Interest Rate Swap [Member]
Derivative [Line Items]
Total		2,090,495	2,142,183
Interest Rate Options Written [Member]
Derivative [Line Items]
Total		64,531	74,741
Interest Rate Options Purchased [Member]
Derivative [Line Items]
Total		82,923	87,020
Foreign exchange contracts [Member]
Derivative [Line Items]
Total		1,277,957	1,105,971
Foreign Exchange Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total		1,172,134	965,301
Foreign Exchange Options Written [Member]
Derivative [Line Items]
Total		28,500	52,845
Foreign Exchange Options Purchased [Member]
Derivative [Line Items]
Total		28,801	53,260
Foreign Exchange Spot [Member]
Derivative [Line Items]
Total		48,522	34,565
Commodities, equities and precious metals contracts [Member]
Derivative [Line Items]
Total		99,071	99,682
Commodities, Equities and Precious Metals, Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total		49,595	49,555
Commodities, Equities and Precious Metals Options Written [Member]
Derivative [Line Items]
Total		18,853	19,495
Commodities, Equities and Precious Metals Options Purchased [Member]
Derivative [Line Items]
Total		30,623	30,632
Credit contracts [Member]
Derivative [Line Items]
Total		119,537	123,714
Other Contract [Member]
Derivative [Line Items]
Total	[1]	$ 380	$ 184

[1] Consists of swap agreements entered into in conjunction with the sales of certain Visa Class B Shares.