Derivative Positions (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Derivative, Notional Amount		$ 232,120	$ 249,705
Derivative Asset, Fair Value, Gross Asset		3,278	3,904
Derivative Liability, Fair Value, Gross Liability		3,829	4,442
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		3,278	3,904
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3,829	4,442
Derivative, Fair Value, Amount Offset Against Collateral, Net		(2,185)	(2,731)
Derivative Liability, Fair Value, Gross Asset		2,185	2,731
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(471)	(371)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		946	1,303
Derivative Asset	[1]	622	802
Derivative Liability	[2]	698	408
Mortgage Servicing Rights [Member] | Interest rate futures [Member]
Derivative, Notional Amount		5,600	16,600
Loans Held-For-Sale [Member] | Interest rate futures [Member]
Derivative, Notional Amount		302	190
Other Trading [Member] | Interest rate futures [Member]
Derivative, Notional Amount		4,900	9,800
Not Designated as Hedging Instrument [Member]
Derivative, Notional Amount	[3]	211,455	229,525
Derivative Asset, Fair Value, Gross Asset	[3]	3,274	3,901
Derivative Liability, Fair Value, Gross Liability	[3]	3,828	4,132
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative, Notional Amount	[3]	7,418	7,058
Derivative Asset, Fair Value, Gross Asset	[3]	106	110
Derivative Liability, Fair Value, Gross Liability	[3]	91	102
Not Designated as Hedging Instrument [Member] | Equity Contract [Member]
Derivative, Notional Amount	[3],[4]	37,362	38,907
Derivative Asset, Fair Value, Gross Asset	[3],[4]	2,384	2,499
Derivative Liability, Fair Value, Gross Liability	[3],[4]	2,648	2,857
Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative, Notional Amount	[3],[5]	1,886	2,017
Derivative Asset, Fair Value, Gross Asset	[3],[5]	13	18
Derivative Liability, Fair Value, Gross Liability	[3],[5]	9	16
Not Designated as Hedging Instrument [Member] | Commodity [Member]
Derivative, Notional Amount	[3]	1,678	1,422
Derivative Asset, Fair Value, Gross Asset	[3]	118	63
Derivative Liability, Fair Value, Gross Liability	[3]	116	61
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Mortgage Servicing Rights [Member]
Derivative, Notional Amount	[3],[6]	25,690	42,021
Derivative Asset, Fair Value, Gross Asset	[3],[6]	18	119
Derivative Liability, Fair Value, Gross Liability	[3],[6]	20	119
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Loans Held-For-Sale [Member]
Derivative, Notional Amount	[3],[7]	5,485	7,590
Derivative Asset, Fair Value, Gross Asset	[3],[7]	15	9
Derivative Liability, Fair Value, Gross Liability	[3],[7]	4	6
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Loans Held-For-Investment [Member]
Derivative, Notional Amount	[3]	183	175
Derivative Asset, Fair Value, Gross Asset	[3]	0	2
Derivative Liability, Fair Value, Gross Liability	[3]	0	2
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Other Trading [Member]
Derivative, Notional Amount	[3],[4]	127,059	126,366
Derivative Asset, Fair Value, Gross Asset	[3],[4]	595	1,066
Derivative Liability, Fair Value, Gross Liability	[3],[4]	894	946
Not Designated as Hedging Instrument [Member] | Credit Risk Contract [Member]
Derivative Liability, Fair Value, Gross Liability	[3],[8]	23
Not Designated as Hedging Instrument [Member] | Credit Risk Contract [Member] | Loans Held-For-Investment [Member]
Derivative, Notional Amount	[3]	825	515
Derivative Asset, Fair Value, Gross Asset	[3]	0	0
Derivative Liability, Fair Value, Gross Liability	[3]	23	11
Not Designated as Hedging Instrument [Member] | Credit Risk Contract [Member] | Other Trading [Member]
Derivative, Notional Amount	[3],[8]	3,869	3,454
Derivative Asset, Fair Value, Gross Asset	[3],[8]	25	15
Derivative Liability, Fair Value, Gross Liability	[3],[8]		12
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative, Notional Amount	[9]	12,900	14,200
Derivative Asset, Fair Value, Gross Asset	[9]	2	2
Derivative Liability, Fair Value, Gross Liability	[9]	1	252
Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Loans Held-For-Investment [Member]
Derivative, Notional Amount	[9]	12,900	14,200
Derivative Asset, Fair Value, Gross Asset	[9]	2	2
Derivative Liability, Fair Value, Gross Liability	[9]	1	252
Fair Value Hedging [Member] | Interest Rate Contract [Member]
Derivative, Notional Amount	[10]	7,765	5,980
Derivative Asset, Fair Value, Gross Asset	[10]	2	1
Derivative Liability, Fair Value, Gross Liability	[10]	0	58
Fair Value Hedging [Member] | Interest Rate Contract [Member] | Fixed Income Interest Rate [Member]
Derivative, Notional Amount	[10]	7,705	5,920
Derivative Asset, Fair Value, Gross Asset	[10]	2	1
Derivative Liability, Fair Value, Gross Liability	[10]	0	58
Fair Value Hedging [Member] | Interest Rate Contract [Member] | Brokered Time Deposits [Member]
Derivative, Notional Amount	[10]	60	60
Derivative Asset, Fair Value, Gross Asset	[10]	0	0
Derivative Liability, Fair Value, Gross Liability	[10]	$ 0	$ 0

[1] At September 30, 2018, $622 million, net of $471 million offsetting cash collateral, is recognized in Trading assets and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2017, $802 million, net of $371 million offsetting cash collateral, is recognized in Trading assets and derivative instruments within the Company's Consolidated Balance Sheets.

[2] At September 30, 2018, $698 million, net of $946 million offsetting cash collateral, is recognized in Trading liabilities and derivative instruments within the Company's Consolidated Balance Sheets. At December 31, 2017, $408 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 Instruments and Trading Activities” in this Note for further discussion

[4] Notional amounts include $4.9 billion and $9.8 billion related to interest rate futures at September 30, 2018 and December 31, 2017, and $274 million and $1.2 billion related to equity futures at September 30, 2018 and December 31, 2017, respectively. 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. Notional amounts also include amounts related to interest rate swaps hedging fixed rate debt.

[5] Notional amounts include $41 million and $49 million related to the Visa derivative liability at September 30, 2018 and December 31, 2017, respectively. See Note 14, "Guarantees" for additional information.

[6] Notional amounts include $5.6 billion and $16.6 billion related to interest rate futures at September 30, 2018 and December 31, 2017, respectively. 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] Notional amounts include $302 million and $190 million related to interest rate futures at September 30, 2018 and December 31, 2017, respectively. 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] Notional amounts include $7 million and $4 million from purchased credit risk participation agreements at September 30, 2018 and December 31, 2017, and $33 million and $11 million from written credit risk participation agreements at September 30, 2018 and December 31, 2017, respectively. These notional amounts are calculated as the notional of the derivative participated adjusted by the relevant RWA conversion factor.

[9] See “Cash Flow Hedging” in this Note for further discussion.

[10] See “Fair Value Hedging” in this Note for further discussion.