Derivative Positions (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2017		Dec. 31, 2016
Document Period End Date		Sep. 30, 2017
Derivative Asset, Notional Amount		$ 132,264		$ 127,456
Derivative Asset, Fair Value, Gross Asset		3,812		4,514
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		4,408		4,902
Derivative, Fair Value, Amount Offset Against Collateral, Net		(2,611)		(3,239)
Derivative Liability, Fair Value, Gross Asset		(2,611)		(3,239)
Derivative Liability, Notional Amount		129,300		146,506
Derivative Liability, Fair Value, Gross Liability		4,408		4,902
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		3,812		4,514
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(303)		(291)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		(1,420)		(1,265)
Derivative Assets	[1]	(898)		(984)
Derivative Liabilities	[2]	377		398
Credit Risk Contract [Member]
Derivative Asset, Notional Amount		5		5
Derivative Liability, Notional Amount		11		13
Credit Default Swap, Buying Protection [Member]
Credit Risk Derivatives, at Fair Value, Net				3
Not Designated as Hedging Instrument [Member]
Derivative Asset, Notional Amount		128,584	[3]	120,396	[4]
Derivative Asset, Fair Value, Gross Asset		3,809	[3]	4,478	[4]
Derivative Liability, Notional Amount		113,300	[3]	130,916	[4]
Derivative Liability, Fair Value, Gross Liability		4,185	[3]	4,556	[4]
Not Designated as Hedging Instrument [Member] | Mortgage Servicing Rights [Member]
Derivative Asset, Notional Amount		23,954	[3],[5]	12,165	[4],[6]
Derivative Asset, Fair Value, Gross Asset		145	[3],[5]	413	[4],[6]
Derivative Liability, Notional Amount		15,062	[3],[5]	18,774	[4],[6]
Derivative Liability, Fair Value, Gross Liability		128	[3],[5]	335	[4],[6]
Not Designated as Hedging Instrument [Member] | Loans Held For Sale [Member]
Derivative Asset, Notional Amount		5,628	[3],[7]	11,774	[4],[8]
Derivative Asset, Fair Value, Gross Asset		13	[3],[7]	134	[4],[8]
Derivative Liability, Notional Amount		4,218	[3],[7]	8,306	[4],[8]
Derivative Liability, Fair Value, Gross Liability		13	[3],[7]	58	[4],[8]
Not Designated as Hedging Instrument [Member] | Loans [Member]
Derivative Asset, Notional Amount		90	[3]	100	[4]
Derivative Asset, Fair Value, Gross Asset		2	[3]	2	[4]
Derivative Liability, Notional Amount		85	[3]	36	[4]
Derivative Liability, Fair Value, Gross Liability		2	[3]	1	[4]
Not Designated as Hedging Instrument [Member] | Loans [Member] | Credit Risk Contract [Member]
Derivative Asset, Notional Amount		0	[3]	15	[4]
Derivative Asset, Fair Value, Gross Asset		0	[3]	0	[4]
Derivative Liability, Notional Amount		620	[3]	620	[4]
Derivative Liability, Fair Value, Gross Liability		8	[3]	8	[4]
Not Designated as Hedging Instrument [Member] | Other Trading [Member] | Interest Rate Contract [Member]
Derivative Asset, Notional Amount		73,673	[3],[9]	70,599	[4],[10]
Derivative Asset, Fair Value, Gross Asset		1,126	[3],[9]	1,536	[4],[10]
Derivative Liability, Notional Amount		57,454	[3],[9]	67,477	[4],[10]
Derivative Liability, Fair Value, Gross Liability		1,014	[3],[9]	1,401	[4],[10]
Not Designated as Hedging Instrument [Member] | Other Trading [Member] | Credit Risk Contract [Member]
Derivative Asset, Notional Amount		2,517	[3],[11]	2,128	[4],[12]
Derivative Asset, Fair Value, Gross Asset		17	[3],[11]	34	[4],[12]
Derivative Liability, Notional Amount		2,534	[3],[11]	2,271	[4],[12]
Derivative Liability, Fair Value, Gross Liability		13	[3],[11]	33	[4],[12]
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Asset, Notional Amount		3,668	[3]	3,231	[4]
Derivative Asset, Fair Value, Gross Asset		126	[3]	161	[4]
Derivative Liability, Notional Amount		3,468	[3]	3,360	[4]
Derivative Liability, Fair Value, Gross Liability		112	[3]	148	[4]
Not Designated as Hedging Instrument [Member] | Equity Contract [Member]
Derivative Asset, Notional Amount		16,512	[3],[9]	17,225	[4],[10]
Derivative Asset, Fair Value, Gross Asset		2,315	[3],[9]	2,095	[4],[10]
Derivative Liability, Notional Amount		28,295	[3],[9]	28,658	[4],[10]
Derivative Liability, Fair Value, Gross Liability		2,836	[3],[9]	2,477	[4],[10]
Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative Asset, Notional Amount		1,786	[3],[13]	2,412	[4],[14]
Derivative Asset, Fair Value, Gross Asset		26	[3],[13]	28	[4],[14]
Derivative Liability, Notional Amount		820	[3],[13]	668	[4],[14]
Derivative Liability, Fair Value, Gross Liability		22	[3],[13]	22	[4],[14]
Not Designated as Hedging Instrument [Member] | Commodity [Member]
Derivative Asset, Notional Amount		756	[3]	747	[4]
Derivative Asset, Fair Value, Gross Asset		39	[3]	75	[4]
Derivative Liability, Notional Amount		744	[3]	746	[4]
Derivative Liability, Fair Value, Gross Liability		37	[3]	73	[4]
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Asset, Notional Amount		3,150	[15]	6,400	[16]
Derivative Asset, Fair Value, Gross Asset		3	[15]	34	[16]
Derivative Liability, Notional Amount		10,550	[15]	11,050	[16]
Derivative Liability, Fair Value, Gross Liability		187	[15]	265	[16]
Fair Value Hedging [Member] | Interest Rate Contract [Member]
Derivative Asset, Notional Amount		530	[17]	660	[18]
Derivative Asset, Fair Value, Gross Asset		0	[17]	2	[18]
Derivative Liability, Notional Amount		5,450	[17]	4,540	[18]
Derivative Liability, Fair Value, Gross Liability		36	[17]	81	[18]
Fair Value Hedging [Member] | Fixed Income Interest Rate [Member]
Derivative Asset, Notional Amount		500	[17]	600	[18]
Derivative Asset, Fair Value, Gross Asset		0	[17]	2	[18]
Derivative Liability, Notional Amount		5,420	[17]	4,510	[18]
Derivative Liability, Fair Value, Gross Liability		36	[17]	81	[18]
Fair Value Hedging [Member] | Brokered Time Deposits [Member]
Derivative Asset, Notional Amount		30	[17]	60	[18]
Derivative Asset, Fair Value, Gross Asset		0	[17]	0	[18]
Derivative Liability, Notional Amount		30	[17]	30	[18]
Derivative Liability, Fair Value, Gross Liability		0	[17]	0	[18]
Interest rate futures [Member] | Mortgage Servicing Rights [Member]
Derivative Liability, Notional Amount		13,300		6,700
Interest rate futures [Member] | Loans Held For Sale [Member]
Derivative Asset, Notional Amount		497		720
Interest rate futures [Member] | Other Trading [Member]
Derivative Asset, Notional Amount		$ 10,100		$ 12,300

[1] At September 30, 2017, $898 million, net of $303 million offsetting cash collateral, is recognized in trading assets and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2016, $984 million, net of $291 million offsetting cash collateral, is recognized in trading assets and derivative instruments within the Company's Consolidated Balance Sheets.

[2] At September 30, 2017, $377 million, net of $1.4 billion offsetting cash collateral, is recognized in trading liabilities and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2016, $398 million, net of $1.3 billion offsetting cash collateral, is recognized in trading liabilities and derivative instruments within the Company's Consolidated Balance Sheets.

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

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

[5] Amount includes $13.3 billion 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.

[6] Amount includes $6.7 billion 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.

[7] Amount includes $497 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.

[8] Amount includes $720 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.

[9] Amounts include $10.1 billion of notional amounts related to interest rate futures and $180 million of notional amounts related to equity 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. Amounts also include notional amounts related to interest rate swaps hedging fixed rate debt.

[10] Amounts include $12.3 billion of notional amounts related to interest rate futures and $629 million of notional amounts related to equity 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. Amounts also include notional amounts related to interest rate swaps hedging fixed rate debt.

[11] Asset and liability amounts include $5 million and $11 million, respectively, of notional amounts from purchased and written credit risk participation agreements, whose notional is calculated as the notional of the derivative participated adjusted by the relevant RWA conversion factor.

[12] Asset and liability amounts include $5 million and $13 million, respectively, of notional amounts from purchased and written credit risk participation agreements, whose notional is calculated as the notional of the derivative participated adjusted by the relevant RWA conversion factor.

[13] Includes $49 million notional amount that is based on the 3.2 million of Visa Class B shares, the conversion ratio from Class B shares to Class A shares, and the Class A share price at the derivative inception date of May 28, 2009. This derivative was established upon the sale of Class B shares in the second quarter of 2009. See Note 12, “Guarantees” for additional information.

[14] Includes $49 million notional amount that is based on the 3.2 million of Visa Class B shares, the conversion ratio from Class B shares to Class A shares, and the Class A share price at the derivative inception date of May 28, 2009. This derivative was established upon the sale of Class B shares in the second quarter of 2009. See Note 12, “Guarantees” for additional information.

[15] See “Cash Flow Hedges” in this Note for further discussion.

[16] See “Cash Flow Hedges” in this Note for further discussion.

[17] See “Fair Value Hedges” in this Note for further discussion.

[18] See “Fair Value Hedges” in this Note for further discussion.