Commitments, Guarantees and Contingencies (Obligations under Guarantee Arrangements) (Details) $ in Millions	Sep. 30, 2015 USD ($)
Credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	$ 797,537
Carrying Amount (Asset)/Liability	(301)
Collateral/Recourse	0
Other Credit Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	1,196
Carrying Amount (Asset)/Liability	(1,042)
Collateral/Recourse	0
Non-credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	2,788,053
Carrying Amount (Asset)/Liability	80,932
Collateral/Recourse	0
Standby Letters of Credit and Other Financial Guarantees Issued
Guarantor Obligations
Maximum Potential Payout/Notional	9,922
Carrying Amount (Asset)/Liability	(188)
Collateral/Recourse	6,962
Market Value Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	678
Carrying Amount (Asset)/Liability	4
Collateral/Recourse	82
Liquidity Facilities
Guarantor Obligations
Maximum Potential Payout/Notional	2,842
Carrying Amount (Asset)/Liability	(4)
Collateral/Recourse	4,473
Whole Loan Sales Guarantees and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	23,485
Carrying Amount (Asset)/Liability	9
Collateral/Recourse	0
Securitizations Representations and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	63,613
Carrying Amount (Asset)/Liability	98
Collateral/Recourse	0
General Partner Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	649
Carrying Amount (Asset)/Liability	71
Collateral/Recourse	0
Less than 1 Year \| Credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	164,281
Less than 1 Year \| Other Credit Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	1
Less than 1 Year \| Non-credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	1,069,489
Less than 1 Year \| Standby Letters of Credit and Other Financial Guarantees Issued
Guarantor Obligations
Maximum Potential Payout/Notional	818
Less than 1 Year \| Market Value Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	26
Less than 1 Year \| Liquidity Facilities
Guarantor Obligations
Maximum Potential Payout/Notional	2,842
Less than 1 Year \| Whole Loan Sales Guarantees and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	0
Less than 1 Year \| Securitizations Representations and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	0
Less than 1 Year \| General Partner Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	71
1 - 3 Years \| Credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	383,709
1 - 3 Years \| Other Credit Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	806
1 - 3 Years \| Non-credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	825,927
1 - 3 Years \| Standby Letters of Credit and Other Financial Guarantees Issued
Guarantor Obligations
Maximum Potential Payout/Notional	1,509
1 - 3 Years \| Market Value Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	397
1 - 3 Years \| Liquidity Facilities
Guarantor Obligations
Maximum Potential Payout/Notional	0
1 - 3 Years \| Whole Loan Sales Guarantees and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	0
1 - 3 Years \| Securitizations Representations and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	0
1 - 3 Years \| General Partner Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	37
3 - 5 Years \| Credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	171,658
3 - 5 Years \| Other Credit Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	340
3 - 5 Years \| Non-credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	301,902
3 - 5 Years \| Standby Letters of Credit and Other Financial Guarantees Issued
Guarantor Obligations
Maximum Potential Payout/Notional	1,311
3 - 5 Years \| Market Value Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	221
3 - 5 Years \| Liquidity Facilities
Guarantor Obligations
Maximum Potential Payout/Notional	0
3 - 5 Years \| Whole Loan Sales Guarantees and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	1
3 - 5 Years \| Securitizations Representations and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	0
3 - 5 Years \| General Partner Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	87
Over 5 Years \| Credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	77,889
Over 5 Years \| Other Credit Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	49
Over 5 Years \| Non-credit Derivative Contracts
Guarantor Obligations
Maximum Potential Payout/Notional	590,735
Over 5 Years \| Standby Letters of Credit and Other Financial Guarantees Issued
Guarantor Obligations
Maximum Potential Payout/Notional	6,284
Over 5 Years \| Market Value Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	34
Over 5 Years \| Liquidity Facilities
Guarantor Obligations
Maximum Potential Payout/Notional	0
Over 5 Years \| Whole Loan Sales Guarantees and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	23,484
Over 5 Years \| Securitizations Representations and Warranties
Guarantor Obligations
Maximum Potential Payout/Notional	63,613
Over 5 Years \| General Partner Guarantees
Guarantor Obligations
Maximum Potential Payout/Notional	454
Primary and Secondary Lending Commitments
Guarantor Obligations
Standby letters of credit	$ 700

Guarantor Obligations, Collateral and Recourse

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

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