Derivative Positions (Additional Information) (Detail) - USD ($) shares in Millions, $ in Millions	1 Months Ended
	May. 31, 2009	Mar. 31, 2016		Dec. 31, 2015
Derivative Asset, Notional Amount		$ 143,941		$ 123,257
Derivative Liability, Notional Amount		117,939		124,755
Other Trading [Member] | Credit Risk Contract [Member]
Derivative Asset, Notional Amount		6		6
Derivative Liability, Notional Amount		10	[1],[2]	9
Derivative Financial Instruments, Liabilities [Member] | Visa Interest [Member]
Number Of Shares Sold To Selected Financial Institutions	3.2
Visa Interest [Member] | Loans [Member] | Other Contract [Member]
Derivative Liability, Notional Amount		49	[1],[2]	49
Interest rate futures [Member] | Loans [Member] | Interest Rate Contract [Member]
Derivative Asset, Notional Amount		546	[1],[2]	518
Interest rate futures [Member] | Other Trading [Member] | Interest Rate Contract [Member]
Derivative Asset, Notional Amount		13,300		12,600
Equity futures [Member] | Other Trading [Member] | Equity Contract [Member]
Derivative Asset, Notional Amount		$ 91		$ 329

[1] Amount includes $518 million of notional amounts related to interest rate futures. These futures contracts settle in cash daily, one day in arrears. The derivative asset or liability associated with the one day lag is included in the fair value column of this table.

[2] See “Economic Hedging and Trading Activities” in this Note for further discussion.