Derivative Financial Instruments - Fair Value of Derivatives and Balance Offsetting (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Derivative assets	$ 66,702		$ 80,055
Derivative liabilities	64,906		78,080
Netting assets	56,849	[1],[2]	68,616	[1],[2]
Netting liabilities	56,849	[1],[2]	68,616	[1],[2]
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements(5)(6)	3,759	[1],[3]	3,870	[1],[3]
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements(5)(6)	1,725	[1],[3]	2,116	[1],[3]
Derivative Asset	6,094		7,569
Derivative Liability	6,332		7,348
Less: Gross amounts of financial instrument collateral received not offset	1,399		1,641
Less: Gross amounts of financial instrument collateral posted not offset	2,652		3,094
Net amount of derivative asset	4,695		5,928
Net amount of derivative liability	3,680		4,254
Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements(5)(6)	3,759		3,870
Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements(5)(6)	1,725		2,116
Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	96	[4]	310	[4]
Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	433	[4]	277	[4]
Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	40,012	[5]	55,397	[5]
Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	40,577	[5]	55,951	[5]
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	18,033	[5]	15,429	[5]
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	17,160	[5]	14,581	[5]
Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1,509	[5]	1,583	[5]
Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	759	[5]	821	[5]
Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	4,277	[5]	4,655	[5]
Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	4,210	[5]	4,708	[5]
Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	60	[4]	278	[4]
Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	322	[4]	212	[4]
Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	10	[4]	32	[4]
Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	112	[4]	62	[4]
Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	26	[4]	0	[4]
Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	(1)	[4]	3	[4]
OTC Cleared [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	12,179	[5],[6]	24,218	[5],[6]
OTC Cleared [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	13,178	[5],[6]	25,468	[5],[6]
OTC Cleared [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	458	[5],[6]	576	[5],[6]
OTC Cleared [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	514	[5],[6]	604	[5],[6]
OTC Cleared [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	15	[4],[6]	75	[4],[6]
OTC Cleared [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	117	[4],[6]	20	[4],[6]
OTC Cleared [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	7	[4],[6]	16	[4],[6]
OTC Cleared [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	0	[4],[6]	0	[4],[6]
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	619	[4],[6]	470	[4],[6]
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	79	[4],[6]	91	[4],[6]
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	27,794	[5],[6]	31,097	[5],[6]
Bilateral OTC [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	27,366	[5],[6]	30,451	[5],[6]
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	0	[4],[6]	0	[4],[6]
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	38	[4],[6]	44	[4],[6]
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	18,033	[5],[6]	15,422	[5],[6]
Bilateral OTC [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	17,151	[5],[6]	14,565	[5],[6]
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	703	[4],[6]	789	[4],[6]
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	190	[4],[6]	148	[4],[6]
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1,423	[5],[6]	1,413	[5],[6]
Bilateral OTC [Member] | Equity contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	1,420	[5],[6]	1,412	[5],[6]
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	0	[4],[6]	0	[4],[6]
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	30	[4],[6]	36	[4],[6]
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1,306	[5],[6]	1,402	[5],[6]
Bilateral OTC [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	754	[5],[6]	815	[5],[6]
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	30	[4],[6]	9	[4],[6]
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	10	[4],[6]	11	[4],[6]
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	3,819	[5],[6]	4,079	[5],[6]
Bilateral OTC [Member] | Credit contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	3,696	[5],[6]	4,104	[5],[6]
Bilateral OTC [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	45	[4],[6]	203	[4],[6]
Bilateral OTC [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	205	[4],[6]	192	[4],[6]
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	3	[4],[6]	16	[4],[6]
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	112	[4],[6]	62	[4],[6]
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	26	[4],[6]	0	[4],[6]
Bilateral OTC [Member] | Cash Flow Hedging [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member] | Interest taxes and other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	(1)	[4],[6]	3	[4],[6]
Exchange Traded [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	39	[5],[6]	82	[5],[6]
Exchange Traded [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	33	[5],[6]	32	[5],[6]
Exchange Traded [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	0	[5],[6]	7	[5],[6]
Exchange Traded [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	9	[5],[6]	16	[5],[6]
Exchange Traded [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	203	[5],[6]	181	[5],[6]
Exchange Traded [Member] | Precious metals contracts [Member] | Not Designated as Hedging Instrument [Member] | Trading Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 5	[5],[6]	$ 6	[5],[6]

[1] Netting is performed at a counterparty level in cases where enforceable master netting and credit support agreements are in place, regardless of the type of derivative instrument. Therefore, we have not attempted to allocate netting to the different types of derivative instruments shown in the table above.

[2] Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements.

[3] Represents the netting of cash collateral posted and received by counterparty under enforceable credit support agreements.

[4] Derivative assets / liabilities related to cash flow hedges, fair value hedges and derivative instruments held for purposes other than for trading are recorded in other assets / interest, taxes and other liabilities on the consolidated balance sheet.

[5] Trading related derivative assets/liabilities are recorded in trading assets/trading liabilities on the consolidated balance sheet.

[6] Over-the-counter (OTC) derivatives include derivatives executed and settled bilaterally with counterparties without the use of an organized exchange or central clearing house. The credit risk associated with bilateral OTC derivatives is managed through master netting agreements and obtaining collateral. OTC-cleared derivatives are executed bilaterally in the OTC market but then novated to a central clearing counterparty, whereby the central clearing counterparty becomes the counterparty to both of the original counterparties. Exchange traded derivatives are executed directly on an organized exchange that provides pre-trade price transparency. Credit risk is minimized for OTC-cleared derivatives and exchange traded derivatives through daily margining required by central clearing counterparties.